Religious Cooperation between Thailand and Sri Lanka in the 19th Century: A Study Based on Exchanged P¯ali Letters

: When it comes to relations between Thailand (Siam) and Sri Lanka (Ceylon), the Buddhist connections between the two countries are often discussed and are highly valued. Communications between Thai and Sinhalese monks can be traced back to the 13th century: the Sukhothai era. These communications were then continuously maintained in the Ayutthaya era and have been up until the present day. Despite being situated far from each other and being separated by the sea, the people in these countries have been interacting through maritime routes and cooperating with each other regarding religious, cultural, financial, diplomatic, and political matters for centuries. The continuous interactions between the two came to a halt in the 18th century due to political instability in both countries. Only in the middle of the 19th century did Buddhists from the two countries resume their travels and interactions, rebuilding their bilateral relations and cooperation. There are very few studies that provide information regarding the religious cooperation between Siam and Ceylon in the 19th century. Religious cooperation between the two countries in the 19th Century has never been thoroughly studied and presented in detail. The purpose of the research paper is to investigate how Buddhists in these two countries cooperated with each other to achieve continuity and solidarity in Theravada Buddhism in both countries. We will address this question by analyzing the available data, which can mainly be found in the form of letters written in the P¯ali language exchanged between Buddhists in the two countries. These letters have been published in P¯alisandes¯aval¯ı in Sri Lanka and in Saman.as¯asana in Thailand.


Introduction
It is evident from the history of Buddhism in South and Southeast Asia that Theravada Buddhism has only survived until the present day due to the cooperation between Buddhists in the kingdoms and countries that existed in the areas where Sri Lanka, Thailand, and Myanmar are situated today.Throughout history, Buddhists in these kingdoms and countries assisted each other in maintaining continuity in Theravada Buddhism and the monastic lineage.
Bilateral cooperation between Thailand (Siam) and Sri Lanka (Ceylon) goes back a very long time.Sinhalese Buddhists, including both monks and lay people, were in contact with Southeast Asian Buddhists even before the formation of the Sukhothai Kingdom, which is generally regarded as the first Siamese Kingdom.According to the available records, despite the countries being situated far from each other, with the sea between them, people would travel between their own country and the other through maritime routes and would cooperate with each other regarding religious, cultural, financial, diplomatic, and political matters.This has contributed immensely to the continued relations between the two countries and to the survival and solidarity of Theravada Buddhism up to today.This interchange also transformed and shaped the forms of Buddhism that currently exist in both countries.Furthermore, the religious, cultural, intellectual, and architectural aspects of both countries were heavily influenced by these interactions.
These interactions came to a halt in the 18th century due to political instability in both countries.Sri Lanka had to deal with colonial invasions, and the whole island came under British colonial rule in 1815 C.E., leaving Buddhists to survive without the support of the ruling authority.The Ayutthaya Kingdom lost its capital to Burmese invasions in 1767 C.E., causing Thais to move their kingdom down to Thonburi, which lasted only 14 years, ending in 1782 C.E.Thereafter, under the leadership of King Rama I, the Rattanakosin Kingdom was established, but the king was engaged in regaining land that had been lost to foreign invasions.Then, after this period of political instability, in the middle of the 19th century, the monastics and lay Buddhists of the two countries started to interact once again by travelling via maritime routes to visit sacred historical sites and to exchange knowledge, texts, relics, and icons.This interaction not only improved bilateral relations and cooperation but also helped to establish the ways in which Theravada Buddhism came to be shared and expressed between the two nations.
In Thailand, this interaction was heavily impacted by the younger brother of King Rama III, who was ordained as a monk during the reign of King Rama III under the name Vajirañāna Thera and later succeeded to the throne as King Rama IV of Siam.Even before his accession to the throne, King Rama IV took the leading role in correspondence with Sri Lanka, and afterwards, with the influence he received from these interactions, he called for Siam to start building bell-shaped chedis in the style of Sri Lanka instead of Prang-style chedis, which had been built prior, in the Early Rattanakosin Period (Amnuayngerntra 2007, pp. 79-80).Furthermore, as the Dhammasami (2004, p. 224) mentions, due to his association with the Ceylonese monks, Vajirañāna Thera gave up some of the Mon-influenced practices that he had adopted earlier.
For Sri Lanka, this cooperation was very much timely and needed, as the country was under British Colonial Rule, and not only did its rulers not wholeheartedly support Buddhist affairs, but they also implemented strategies to suppress Buddhism (George 1988, p. 14).Moreover, during this period of time, Christian missionaries actively engaged in spreading their religion with the support of British rulers.They were implementing every possible tactic to discredit Buddhism and to promote Christianity in the country.In this manner, the colonial government did not render much support to Buddhists affairs (David Scott 1996, pp. 7-23).From the beginning, Buddhism had traditionally maintained a close relationship with the ruling monarchy, receiving both support and protection from the kings, so the overthrow of the last king of Kandy by the British had far-reaching consequences for Buddhism (George 1988, p. 14).Therefore, though this point has received little attention in the existing literature, the financial and moral assistance offered by Siamese monks to the kings of Siam in ecclesiastical matters contributed immensely to the preservation and continuity of Buddhist practices in Sri Lanka.
Another significant aspect of this interaction is that this bilateral relationship between the two countries at this time can be seen as a distinctive form of cooperation because, unlike in earlier or later periods, the governing authorities of Ceylon were not involved in supporting this process.Hence, there was no government-to-government diplomacy involved during this period, and the relationship between the two countries was purely based on Buddhist affairs and led mainly by Buddhist monastic leaders.
Nevertheless, when considering the relationship between Thailand and Sri Lanka, many have focused their attention mainly on the journey of the group led by Upali Thera from Ayutthaya Kingdom, who went to Sri Lanka to revive the monastic order and Buddhism in the Kandyan Kingdom in the 18th century, and on the journeys that had occurred before that period.For instance, in Phocana and Sukprasert's article, political and religious interactions between the Tambalinga Kingdom of Thailand and the Dambadeniya Kingdom of Sri Lanka have been documented (Phocana Suvaco and Sukprasert 2019).Similarly, Sri Lankan inscriptions from the Dvāravati period were briefly analyzed by Rohanadeera in his article (Rohanadeera 1988, pp. 47-63).The interactions between the two countries from the 13th century to the 15th century were studied by Paranavitana and presented in his article (Paranavitana 1932, pp. 190-213).This textual study, published in 1932, provides a summary of all the preliminarily traceable incidents that occurred in that period, without going into depth with regard to every aspect.Lorna Dewaraja, in her article (Lorna Dewaraja 2003, pp. 75-90), discusses the contribution of Ven.Upāli and his followers to the revival of Buddhism in Sri Lanka in the Kandyan period.Rohanadeera, in his paper (Rohanadeera 1988, quotes three stanzas from the Telakat .āhagāthā and starts to explore cultural relations between the two countries in the early Dvaravati Kingdom.Furthermore, Tansen Sen (2019), having pointed out the lack of studies in modern scholarship on the transmission of Buddhism via maritime routes in general, and specifically the transmission of Buddhism in Southeast Asia, focuses his attention on highlighting the Sinhalese contribution to the spread of Tantric doctrines through maritime routes.The discovery of a Sinhalese version of a traditional meditation text, "borān yogāvacara kammat .t . hāna", and the introduction of this meditation from Siam to Sri Lanka, along with the Siyam Nikāya in the 18th century and its influence and popularity, have been discussed by Kate Crosby et al. (2012).
However, there are several studies that contain limited information regarding cooperation between Siam and Ceylon in the 19th century.Dhammasami (2004, pp. 223-24), in his Ph.D. dissertation, dedicates two pages, with very limited related information, to explore the journeys organized by Vajirañān .a Bhikkhu for Siamese Bhikkhus; he sent them to Ceylon to bring canonical texts back to Siam.A summarized report of those journeys and the texts brought back to Siam is provided without any mention of the journeys made by Sinhalese Bhikkhus to Siam.One of the letters that also appears in Pālisandesavali, a Pāli letter about monastic boundaries sent by Vajirañān .a Thera (who later became King Rama IV) of Siam, has been transliterated into Roman scripts by Petra Kieffer-Pülzz (2011).Apart from the above-mentioned publications, cooperation between the two countries in the 19th century has never been thoroughly studied and presented.
In order to address the above-mentioned gap in the existing literature, we investigated how the Buddhists in the two countries cooperated with each other in the 19th century.This will hopefully contribute to our understanding of the development of the cooperation that led to the continuity of Theravada Buddhism in both countries.

Methodology and Scope
In this research, in order to study the interactions that occurred during this period, we focused our attention on studying the available data, which mainly exist in the form of letters written in the Pāli language and exchanged between Buddhists in the two countries.These letters demonstrate the bilateral relationship that was required in order to continue the long-lasting relationship between the two countries and improve Buddhism and the monastic order in the two countries.We summarily translated relevant parts of these Pāli letters into English and treated them as primary sources.Then, to achieve the aforementioned aims, we analyzed the data, along with other relevant data that were available as secondary sources in the form of books, articles, dissertations, and websites available in Thai, Sinhalese, and English.
Among our main sources are the Pāli letters exchanged between the two countries, which have been published in Sinhalese scripts in the book titled "Pālisandesāvali" (Buddhadatta 1962).These contain rich information regarding the religious, political, cultural, educational, diplomatic, and historical relationships between the two countries.Mainly, the letters in the book are letters exchanged between senior monks of Sri Lanka and senior monks of Thailand and Myanmar.There are also several letters exchanged with bureaucratic personals in the respective countries.Most notably, there is a special letter sent by King Rama IV of Thailand to Bulathgama Dhammalankara Sirisumanathissa Thera in Sri Lanka explaining the circumstances that led him to disrobe and become the monarch of Thailand.There are sixteen letters that were exchanged between Siam and Ceylon, twelve of which were sent from Siam to Ceylon, and five of which were sent from Ceylon to Siam.All these letters, which were exchanged between the years 2385 B.E. (C.E.1842) and 2395 B.E. (C.E.1852), provide historical records of the incidents and interactions that happened before and during that period of time.
Another main source available on the Thai side, in Thai script, is a collection of nine letters that were sent from Siam to Ceylon between the years 2385 B.E. (C.E.1842) and 2388 B.E. (C.E.1845).These letters were published as a book by Wat Bavornnivet and Fine Art Department of Thailand in 1952.This publication's title in Thai is "Samanasāsana: Phra Dhammayuttika Mee Pai Yang Lankadveep", meaning "Ecclesiastical letters: Sent by Dhammayuttika Monks to the Island of Lanka".The book includes letters sent by Siamese monks to Ceylon.Three out of the nine letters in this collection can also be read in the Pālisandesavalī.However, in this publication, there are six other letters that are not obtainable on the Sinhalese side.

Resuming Interactions
One letter (Buddhadatta 1962, pp. 8-14) sent by a group of ten senior monks of the Pavaranivesa Temple of Bangkok to senior monks and others on the Island of Sinhalese (Sīhaladīpa) in B.E. 2385 (C.E.1842) contains many interesting details concerning interactions between Buddhists in the two countries.The nature of Buddhist religious visits and the diplomatic procedures around welcoming the Sinhalese Buddhist group to Thailand can be elucidated from this letter, specifically from the part that mentions the way in which a group of Sri Lankan Buddhists who visited Bangkok during the reign of King Rama III (Paramadhammikarājā) in the year 2383 B.E. (1840 C.E.) were received and granted an audience with the king.It is mentioned in this letter that, after being informed of their arrival, the king stated, "I heard the people of the Island of the Sinhalese (Sīhaladīpa) are followers of Buddha's teachings (buddhasāsanikā) but we have not been in contact with them for a long time and I have no information about their arrival prior to this time, why have they decided to come now. ... Anyhow, we should treat them accordingly as they are claiming to be followers of the Buddha's teaching and monks".This indicates that, prior to the arrival of this group of monks, there had been no official acknowledgement of the arrival of Sinhalese monks or lay Buddhists during the reign of King Rama III, which started in the year 1824.Most likely, there had not been any visits from significant Buddhist groups from Sri Lanka since the beginning of the 19th century.The king was born in 1788 and was an active member of the ruling dynasty; if there had been any official visits, then the king would have known.
The courtesy and the support that the Sinhalese Buddhist group received from the king, the ministers, and the monks were also recorded in this letter.Having been granted residence at Wat Bowonniwet Temple (Pavaranivesa), this group of Buddhists, which consisted of four fully ordained monks, namely Saddhātissa, Kakusanda, Vipassi, and Revata; a novice monk named Siddhattha; and two lay people, mentioned as the secretary (Lekham) and Band .a, were taken to visit sacred sites, such as the Temple of the Emerald Buddha (Siriratanapat .imāghara), Phra Pathomchedi Temple (Pat .amamahācetiya), and Wat Phra Phutthabat (Buddhapādalañcanacetiya), and to meet important senior monks, such as the Supreme Patriarch (Sangharājā) of Mahānikāya Chapter.They were also brought to significant temples in ancient cities, such as Saraburi (Salapurī), Suphanburi (Suvannapurī), and Phetchaburi (Vajirapurī), as well.
Upon the request of the Sri Lankan monks, some Pāli texts that were not available in Sri Lanka were given to them, so that they might be taken back there.The texts mentioned in the letter are Abhidhānappadipikāt .ikā, Abhidhammatthavibhāviniyā, Mangalatthadīpanīpakaran .a, and Ganthābaran .at .ikā.
Furthermore, it is mentioned that a group of five Siamese monks and five lay assistants was sent to the island of Lanka (Lankadīpa) onboard the same ship.The names of the monks were Buddhañān .a, Amara, Subh ūti, Gambhīra, and Buddhavīra.These five monks belonged to the Dhammayuttikā (adherers to the Dhamma) sect.

Transportation
The primary mode of international transportation at that time was represented by the maritime routes between South Asia and Southeast Asia.Apart from travelling from one place to another and taking goods along with them, the monks also exchanged letters and goods by sending them via sea routes, in the care of merchants.We can deduce from several letters that, during the earliest stage, the Sinhalese Buddhist groups who visited Siam travelled with merchant ships belonging to people of many different nationalities and religious beliefs.It is mentioned in a letter (Buddhadatta 1962, p. 9) that Siamese monks sent two letters to Ceylon on a ship belonging to Muslims (Musalamānānam .Nāvā).In the same letter, it is mentioned that King Rama III was concerned that the Sinhalese Monks might face difficulties travelling onboard ships belonging to English (Im .grīsi) and Muslim (Musalamāra) sailors.However, after receiving the royal support of King Rama III, most of the Buddhist groups travelled with Siamese ships.Specific details of the journeys made by the monks, and the ways in which they exchanged goods and information, will be given in several places throughout this paper.

The Role of King Rama III
As can be seen from the information available in the letters, King Rama III genuinely and wholeheartedly supported cooperation between Buddhists in these two countries.It is evident from the letter sent in the year 2385 B.E. (Buddhadatta 1962, pp. 8-14) that, when this group of monks and lay Buddhists were offered an audience with the king while the king was visiting Pavaranivesa Temple for the Katina Robe offering ceremony, they informed the king of their intention to return to Sri Lanka.Then, the king, out of concern for their safe return, asked them to travel on board a Siamese ship, as they would receive better treatment during the journey.Moreover, he ordered that, "from now onward may the Siamese ships go to Sri Lanka and may the monks who wish to visit Buddhist sites in Sri Lanka travel on those ships.May Sinhalese monks and their lay assistants who wish to visit Siam travel onboard Siamese ships free of charge as all costs will be borne by the Monarch. ... ..because the association with the followers of the Buddha's teachings (Buddhasāsanikā) from other countries is good indeed".When they were about to set off for Sri Lanka, they were brought to meet the king in the royal palace, and the monks were offered good-quality bowls and robes, while the lay followers were given clothes and money for the expenses during the journey.
There are many letters that have mentioned the financial support offered by the king for activities involving religious cooperation between the two countries.Apart from the immense financial support that the king provided, with absolute monarchy being the system of governance in Siam, the king's approval of these interactive activities was vital in allowing and encouraging cooperation between Buddhists in the two countries.

Dhammayuttika Monks Taking the Leading Role in Siam
In a letter (Buddhadatta 1962, pp. 90-94) sent by Devamoli Mahathera to the monks of Asgiriya Temple (hayagiri vihāravāsī) in the year 2389 B.E. (1846 C.E.), a summary of the history of Buddhism in Thailand up until the contemporary period is given.The existence of the two sects, namely Syāmavam .sika and Rāmaññavam .sika, has been stated in this letter, with more emphasis placed on elaborating the history of the Ramaññavam .sika sect.It is also mentioned that the Syāmavam .sika sect is referred to as Mahānikāya due to its large number of members, whereas the other sect is called Cullanikāya due to it having fewer members.The fair and equal treatment of the king toward both these sects is illustrated in the letter.It is further mentioned in the letter that only the monks who belong to the Rāmañña sect were travelling abroad at that time, as the monks of the other sect were unwilling to associate with people from different countries and religions.
In a letter (Buddhadatta 1962, pp. 39-49) sent by a group of ten Dhammayuttika monks to all sects of monks on the island of Lanka (Lankadīpa) in 2387 B.E. (1844 C.E.), the names of the monks are mentioned.They are as follows: 1.
Another letter (Buddhadatta 1962, pp. 50-58) was sent by the Executive Committee of Ten Monks of Dhammayuttika Nikāya to the monks of all sects in Sri Lanka and to the lay Buddhists who were interested in learning about the situation regarding Buddhism in Siam.In the letter, the Committee give a detailed report of their perspective on Buddhism in both countries (Ceylon and Siam).
A letter (Buddhadatta 1962, pp. 67-69) sent by Sobhitasirivisuddhivam .sa Thera, at the request of Vajirañān .amakut .asammatavam .sa Thera, the chief monk of Pavaranivesa Temple, to Saddhātissa Thera of Colombo and the senior and junior monks of Burmese Lineage (Mrammavam .sikā), indicates that a group of Sinhalese monks and lay followers had visited Siam on a ship and were given accommodation at Pavaranivesa Temple (Buddhadatta 1962, pp. 67-69).This exemplifies the fact that, at the time, Parananivesa Temple, which was the headquarters of the Dhammayuttika sect, had been allocated as accommodation for visiting Sinhalese monks, as the monks of this sect were actively engaged in the task of reviving cooperation between the two Buddhist countries.
It also mentions that the monk Subh ūti, who previously went to Lanka and brought back Sinhalese texts, was given the royal title of "Varasamuddamuni" by the king for bringing so many books back to Siam.Hence, he would not be able to go to Sri Lanka again next time.Therefore, monks who had been to Sri Lanka, such as Pilinda, Amara, or Buddhavīra, and some monks who had never been to Sri Lanka, such as Anoma or Hemaka, would be sent to Sri Lanka next time (Buddhadatta 1962, pp. 67-69).
The same letter further states that some monks of the Upāli sect had sent letters to the writer, requesting that he invite monks of the Mahānikāya sect to go to Sri Lanka.The author, who belonged to the Dhammayuttika sect, states that it was not his duty to do so and that the monks of the Upāli sect should have come and invited them themselves (Buddhadatta 1962, pp. 67-69).Even though, in the letters, the Dhammayuttika monks state that there was unity among the monks of the two fraternities in Siam, statements like this imply that there was competition between them, as well.

Competition to Play the Main Role in Ceylon
The monks in Ceylon also competed with each other to play the leading role in corresponding with the Siamese monks.In the letter sent by the Senior monks of Siam Nikaya in the year 2388 B.E. (1845 C.E.), they claim that only the monks who belonged to the Siam Nikāya were recognized by the kings and the rulers of the country and that the other sect, which was established by weaver-caste people (Pesakārā) who dwelled on the seashore, was brought over from Avantirat .t . ha.The letter further states that the monks of Siam sect (Upāli Nikāya) did not perform monastic activities together with the other sects established by low-caste (hīnajātika) people from the outskirts of the country, as they were marginalized by the kings of the country (Buddhadatta 1962, p. 88).This indicates that the emergence of new sects and their association with the Siamese monks who mainly belonged to the Dhammayuttika sect were not tolerated by the Sinhalese monks of the Upāli Nikāya.Hence, they wrote this letter to the monks of Siam, asking that their cooperation and recognition be only with the monks of the Upāli Nikāya (Pālisandesāvalī, p. 88).
A letter (Buddhadatta 1962, pp. 36-37) sent by the Sangharāja of Thailand, Ariyavam .sāgatañān .apariyattivara of Wat Rajaburana (Rājapun .n .a 1 ), addressed to Sumangala Mahanāyaka Thera of Malwatta (Pupphārāma) and Gun .aratana Mahanāyaka Thera of Asgiriya (Hayagiri Vihāra) in Kandy (Sen . khandaselanāma Siriwadd . hannagara) in Ceylon in the year 2387 B.E. (1844 C.E.) states that, after reading the letters sent from Ceylon earlier, the author perceives there to be no unity among the two sects of monks in Lanka, and he further advises them to be united in order to facilitate the development of Buddhism.Moreover, he mentions that the fact that Sinhalese monks of the Burmese tradition (marammavam .sikā) were not performing monastic affairs with other Sinhalese monks of the Siam Tradition (Upālivam .sikā) was also not a good practice and that they should have been persuaded to unite in order to make Buddhism shine again like in ancient times.He later praises the promise of Mahatheras such as Mahanayaka Thera of Malwatta Chapter to seek and lend Pāli texts that were not available in Thailand.The king was said to be very happy about it and determined to support the copying of those texts which were not available in Siam, to complete the collection of Pāli texts in the country.
In a letter sent by Atthadassi Thera of Vanavāsi Vihāra of Bentaragama in the year 2388 B.E. (1845 C.E.) to Vanarathana Sangharāja Thera of Siam, a detailed exposition of the situation of Buddhist monks in Sri Lanka is presented.He also raises many points regarding the accuracy of the monastic lineage of monks in Siam and Ceylon.
A letter (Buddhadatta 1962, p. 87) was sent by the senior monks of Siam Nikaya of Ceylon to oppose the letter sent by Atthadassi Thera and to downgrade the monks who belonged to other sects.It is also mentioned in the letter that there were two groups of Siamese monks; one group consisted of five monks, including the monks Subh ūti and Amara, and the other group consisted of seven monks, including the monks Subh ūti and Pilindavaccha, who visited Ceylon.After arriving in Colombo, they were escorted by a traditional procession from Colombo to Kandy (Sirivad .d .hanapura) and given accommodation at Malwatta Temple (pupphārāma vihāra).They were provided with all the necessities during their stay and brought to see the Sacred Tooth Relic.This exemplifies the intention of the monks of Siam Nikāya (Upālivam .sikā) to discredit all other sects that existed in Ceylon and to express the importance that they had given to the monks who arrived from Siam.
In a letter (Buddhadatta 1962, pp. 39-49) sent to monks in Ceylon, Dhammyuttika monks report that they had learned from monks named Saddhātissa and Kakusandha, who had recently visited Siam, about the existence of a sect of monks belonging to a Burmese tradition (Mrammavam .sikā) in Sri Lanka.This letter implicitly demonstrates that sectarian divisions influenced how the Dhammyuttika monks viewed the Sinhalese monks who belonged to each sect and chapter.The tetter states that this sectarian division was obvious to the monks in Siam from the letters that they received and their conversations with the Sinhalese people that they met.

The Role of King Rama IV
The king had been a monk before ascending to the throne and was known as Vajirañān .a Makutasammatavam .sa Thera.He was the abbot of Pavaranivesa Temple and also the leading monk of the newly formed Dhammayuttika sect.Moreover, he had been the main figure in the correspondence with the monks and lay people of Ceylon.In fact, most of the letters exchanged between the two countries in this period included the name Vajirañān .a as the main character who organized all the interactions and visits on the Siamese side.
Even after disrobing and ascending to the throne, he had been interacting with the monks of Ceylon.A letter (Buddhadatta 1962, pp. 106-11) sent by King Mongkut (makut .asammatadevavam .sissara), who previously interacted with Sri Lankan monks while being a leading monk of the Dhammayuttika sect under the monastic name "Vajirañāna", in the year 2390 B.E., is very important and can be found in this collection.The letter, written by the king himself, describes the circumstances that led him to disrobe and accept the throne in his own words.This historical document gives a clear picture of what happened between the demise of the previous king and King Rama IV ascending the throne.
The contemporary diplomatic norm that only kings were allowed to directly address or send messages to the king of Siam is mentioned at the end of the letter, with the suggestion of an alternative way of sending letters to him.The alternative way is not specifically mentioned in this Pāli letter, but it suggests that the reader refer to the instructions given in another letter written in English, which does not appear in the book.
In a letter (Buddhadatta 1962, pp. 119-21) sent by Piyaratanatissa Thera in Ceylon to Sobhitasirivisuddhivam .sa in Siam in the year 2395 B.E., a message to be passed on to the King Makut .asammatidevavam .sa can be read.The receiver is asked to thank the king for the set of robes sent by the king to five senior monks, including the Nayaka Thero of Sailabimbārāma.Furthermore, in this letter, the establishment of the Rāmaññanikāya in Sri Lanka by a group of 10 monks who went to receive higher ordination from Ham .sāvatī City in Burma is elaborated, and it is mentioned that the writer had sent gifts and letters to the king, the monks of Pavaranivesa Temple, and the ten governor-monks of the Dhammayuttika sect.He further enquires as to whether the Rāmaññavam .sa of Siam was of the same lineage.
All these letters clearly indicate that King Rama IV, during his time as a monk, strived to develop and facilitate the bilateral relationship between Buddhists in the two countries.Even after disrobing and ascending to the throne, he still corresponded with the Sinhalese monks regarding various matters.

Exchanging Knowledge
The exchange of letters between the leading monks of both countries, as can be seen from these examples, is, of course, a way of exchanging information regarding monastic matters, in order to gain new knowledge on ecclesiastical procedures, disciplinary rules, the teachings of Buddha, the history of Buddhism, the lineage of monastic sects, history, news, and the introduction of prominent monks and lay Buddhists.
In a reply letter to the inquiry of Lankagoda Dhīrānanda (Buddhadatta 1962, pp. 152-76), Vajirañāna Sangharāja answered the questions regarding the boundary measurement of village boundaries (Gāma Sīmā) in an analytical manner.This exemplifies the exchange of knowledge between the monastic institutions of two countries regarding ecclesiastical matters.
As is apparent from many of the letters, knowledge about the history of Buddhism in both countries was exchanged.In a letter (Buddhadatta 1962, pp. 86-89) sent by the head monks of the Malwatta and Asgiriya Chapters to Vajirañān .a Thera in the year 2388 B.E. (1845 C.E.), the history of the religious relationship between Siam and Ceylon is summarized as follows.During the reign of King Parakkamabāhu of the Island of Sinhalese (Sīhaladīpa), Buddhism had been brought to Siam and established there.Later, during the reign of King Kittisiri of Lanka, a message and many gifts were sent to King Mahādhammika.A group of Siamese monks, namely Upāli, Ariyamuni, Brahmajoti, Mahāpuñña, Candasāra, Sāracanda, Man .ijoti, Indasuvanna, Candajoti, Brahmasara, Sudinna, Suvan .n .a, Dhammajoti, and Sagun .a, were sent to Sri Lanka in 2296 B.E.They re-established Buddhism by performing higher ordination (Upasampadā) on more than 700 monks and ordaining about 3000 novices.
The second group of monks, consisting of Visuddhācariya, Vidarsanācariya, Vajirañān .amuni, Candasara, Dhammasara, and Indajoti, arrived in Sri Lanka and stayed for three years.Before returning to Siam, they performed higher ordination on 300 monks and taught Vipassana meditation.
It also mentions that, in the year 2360 B.E., a group of eight monks, namely Candajoti, Puññappiya, Indaratana, Ñān .ajoti, Buddhadhara, and Dhamamdhara, came to Malwatta (Puppārāma) Temple in Kandy.After observing the monastic activities performed by the Sinhalese monks, they confirmed them to be accurate, without any faults.They also returned to Siam after staying for about a year and seeing the Sacred Tooth Relic.
The history of Siamese Buddhism and the monastic institutions in Siam are elaborated in a letter (Buddhadatta 1962, pp. 90-94) sent by Devamoli Thera of Siam to the Sinhalese monks of Asgiriya Temple (Hayagirmahavihāra) in the year 2389 B.E.The letter enumerates the history of the two major monastics sects that existed in Thailand, namely the Lineage of Siam (Siyāmavam .sikā) and the Lineage of Mon (Rāmaññavam .sika), with more emphasis on the lineage of the Mon.Starting from Buddha's time, it tells of the sending of missionary monks by King Ashoka in different directions, the simultaneous existence of two major Thai capital cities, Phitsanulok (Vin .huloka) and Ayutthaya (Ayujjhiyā), King Maha Thammaracha ruling the whole of Siam from the capital city of Ayutthaya, and King Naresuan becoming the king of Siam.The establishment of the Lineage of Mon (Rāmaññavam .sika) in Siam is said to have happened during the reign of King Naresuan (Narissaro).The ordination of Prince Makut .asammatavam .sa, who was a half-brother of King Rama III (Paramadhammikarāja), to join the Mon lineage and his receiving the monastic name Vajirañān .a is also mentioned.The letter also expresses that the king treated the monks of both lineages the same way, without any bias.
The monks from the two countries exchanged monastic knowledge, historical knowledge, and news from their country through these letters, in this manner.

Exchanging Buddhist Texts
From the letters, it is evident that the monks of each country exchanged Buddhist texts that were not available in their respective countries.In a letter (Buddhadatta 1962, p. 8) sent in the year B.E. 2385 (C.E.1842), it is mentioned that, upon the request of the Sri Lankan monks, some Pāli texts that were not available in Sri Lanka were given to them to be brought to Sri Lanka.The texts mentioned in the letter are Abhidhānappadipikāt .ikā, Abhidhammatthavibhāviniyā, Mangalatthadīpanīpakaran .a, and Ganthābaran .at .ikā.
In the letter (Buddhadatta 1962, pp. 59-66) sent by the group of ten Dhammayuttika monks to all sects of monks on the island of Sri Lanka (Lankadīpa) in 2387 B.E. (1844 C.E.), it is mentioned that, in the last year, a committee of learned monks and lay people appointed by the king had completed the transliteration of 15 texts borrowed from Sri Lanka.They further suggest that Sinhalese monks should make copies of the books that were not available in Siam and send them to Siam to be kept permanently, rather than just lending books, as they would like to keep these important books for proofreading.The Siamese monks were willing to pay the cost of the copying process.
Another letter, sent by executive monks of the Dhammayuttika sect in Siam to Bopagoda Siri Sumana Thera in 2387 B.E. (1844 C.E.), mentions borrowing 13 texts from Ceylon to be taken back to Siam in order to copy them and send the manuscripts back to Lanka (Bavornnivet 1952, p. 141;Buddhadatta 1962, pp. 29-33).In a letter (Buddhadatta 1962, p. 17) sent by Dhammayuttika monks to the Buddhists in Ceylon in the year 2387 (1844 C.E.), it is mentioned that, on the request of Dhammakkhandācariya of Ceylon, Siamese monks lent the texts of Buddhānuparivattapakaran .a and Cakkavāladīpanī to the Sinhalese monks, on the condition that they would return them after making copies.
According to another letter sent by the leading monks of the Asgiriya and Malwatta Chapters to Vajirañān .a Thera of Siam in the year 2388 B.E. (1845 C.E.) (Buddhadatta 1962, p. 87), four canonical texts, namely Sam .yuttanikāya, Parivāra, Cullavagga, and Mahāvagga, were sent to the king of Siam in the care of a group of Siamese monks led by Subh ūti Bhikkhu and Amara Bhikkhu.

Exchanging Gifts and Sacred Icons
The exchange of gifts was also a way of maintaining a cordial relationship between the Buddhists in both countries.In a letter (Buddhadatta 1962, p. 65) sent by the group of ten Dhammayuttika monks to all sects of monks on the Island of Lanka (Lankadīpa) in 2387 B.E. (1844 C.E.), it is mentioned that the people of Ceylon and Siam were like beloved relatives, as people in both countries were followers of Buddha's teaching.It is also stated that earlier people in the two countries did not receive news about each other due to the lack of ship travel, but now, with the commencement of this form of travel, they were able to receive news about each other and also exchange gifts, allowing them to become closer.
In this letter (Buddhadatta 1962, p. 65), a question is raised regarding the norm among Siamese Buddhists to ask for sacred relics from Sinhalese monks and people who came to visit Siam.As is explained, the Siamese people, knowing that sacred relics had been brought from India to the Island of Lanka from time to time, and been enshrined in Stupas in many locations in the Island of Lanka, thought that many sacred relics would have been kept by the Sinhalese people.Nevertheless, most of the relics that Siamese people were receiving at this time from Ceylon did not look like real relics, but like gravel, sand, seashells, and grain.Therefore, though people did not say so in public, out of respect and having good manners, in private, they criticized the relics as being inauthentic.On the other hand, the Buddha images, as mentioned in the letter, were admired and sought after by the Siamese people, as those images were brought from Ceylon.Furthermore, it is mentioned that, if the king were able to acquire a real sacred relic from a specific place of enshrinement, he would be very pleased and elated.
It is mentioned in the letter (Bavornnivet 1952, p. 173) sent by Dhammayuttika that the Siamese monks sent gifts, such as a set of silk robes, a silk monastic bag, a Chinese ceramic jar, a Chinese ceramic pot, a Thai monastic fan, and two watches, to Ven.Sobhitasiri of Ceylon.
On another occasion, a crystal mirror and an ivory monastic fan handle were sent to Vajirañān .amakutasammata Thera.A sitting Buddha statue was sent to the Sangharāja of the Mahanikāya sect.Another sitting Buddha statue was sent to Jinorasa Mahā Thera of Chetupon (Jetavana) Temple (Buddhadatta 1962, p. 87).
Another letter sent by Sobhitasirivisuddhivam .sa Thera, at the request of Vajirañān .amakut .asammatavam .sa Thera, the chief monk of Pavaranivesa Temple, to Saddhātissa Thera of Colombo and to the senior and junior monks of Burmese Lineage (Mrammavam .sikā), indicates that a group of Sinhalese monks and lay followers had visited Siam on a ship and were given accommodation at Pavaranives Temple.They had brought many gifts and letters to be given to the king, ministers, and well-known monks of the Dhammyuttika sect.In this letter, an important diplomatic manner was revealed.The writer informs the recipient that some monks of the Upāli sect (upālivam .sikā) had sent some parcels directly addressing the king of Siam, which is not a proper diplomatic practice, because, usually, whatever is intended to be given to the king should be addressed to a responsible minister, who would decide whether to give it to the king or not.Otherwise, only a king of another Kingdom could directly send a letter or any parcel to the king.Anything that had been sent addressed directly to the king by a commoner should either be destroyed or be sent back (Buddhadatta 1962, pp. 67-68).
A letter sent by the Sangharāja of Siam to Sumangala Mahanayaka Thero of Malwatta (Pupphārāma) and Gun .aratana Mahanayaka Thera of Asgiriya in Kandy, Sri Lanka, in the year 2387 B.E. (1844 C.E.) indicates that the group of five Siamese monks who had been to Ceylon had returned to Siam and brought with them a group of two Sinhalese monks, two Sinhalese novice monks, and five Sinhalese lay followers.They all visited the Sangharāja and handed over a message from Ceylon and other goods that they had brought from Ceylon, i.e., an ivory casket with a relic enshrined and two Buddha statues.He also mentions that an ivory casket with two relics enshrined that the monks had brought from Ceylon for the king had already been sent to him (Buddhadatta 1962, p. 36).

Giving Financial Support
As the primary mode of transportation between the two countries at that time was sailing ships, the monks and their followers travelled with sailors and merchants, who were mainly engaged in commercial activities.It can be deduced from a letter that it took them 27 days to arrive in Singapore (Sim .hapura) from Colombo, and then it took 12 days for them to reach Chaophraya River from Singapore (Bavornnivet 1952, p. 128).Many of these ships did not belong to Buddhists; hence, they did not offer special treatment to the monks who traveled on board their ships.Knowing about the hardships faced by Sinhalese monks and lay followers, and considering the Sinhalese people to be Buddhists who had protected Buddhism and Buddhist practices amidst many difficulties, King Rama III of Siam announced that Siamese ships should let Sinhalese people who were followers of Buddha's teachings (Buddhasāsanikā) to travel freely on their ships to and from any destination, without asking them for any payment, as the royal treasury of Siam would bear all of those costs (Buddhadatta 1962, p. 65).
The king, upon learning of the endeavor undertaken by Ven.Sumana and others in finding the texts that had not been available in Siam, was elated and ordered that some gifts be sent to the monk.It is also interesting to note that the Siamese monks offered to pay the fees of the people who transcribed and transliterated the texts to be sent to Siam (Buddhadatta 1962, pp. 59-66).

Giving Moral Support
In the year 2392 B.E., Ven.Devamoli, secretary to a Sangharājā named Mahanāga, sent a letter (Buddhadatta 1962, pp. 112-18) addressed to all the chief monks of Myanmar Lineage (marammavam .sika), mainly to inform them of the passing away of the Chief Sangharājā (Mahānāgasangharājādhipati).In the letter, a detailed biography of the deceased monk is provided.It is mentioned that, although they had never met him in person, there were Sinhalese monks in Ceylon who had regarded this monk as their father.This demonstrates that the senior monks of Siam had been regarded highly by the Sinhalese monks.This could be because Ceylon was under British rule at the time and also because the sectarian division of monks in Ceylon was very severe, and the sects that were discriminated against by the others looked to the monastic institution of Siam as their moral supporters.
Not only the senior monks but also the Monarchs of Siam had been regarded by both monks and lay Buddhists in Ceylon as the guardians of the Buddhist faith and the father figures who gave both financial and moral support to the Buddhists in Ceylon.The moral support rendered by King Rama III and King Rama IV both before and after their coronations had an immense impact on the Buddhists in Ceylon who did not receive proper patronage from the colonial government of Ceylon.
The letter sent by Bopagoda Sirisumana to the Dhammyuttika monks in the year 2387 B.E. reveals that influential ministers on the island of Sri Lanka, although Buddhist, were not engaging in Buddhist activities publicly due to the fear that their (colonial) lords would condemn them.Furthermore, the author asks Siamese monks to send letters to the monks of Sri Lanka to encourage them to behave properly (Buddhadatta 1962, p. 27).
Knowing the extreme sectarian division that existed among the Ceylonese monks, the Siamese monks always advised the monks in Ceylon to unite, as can be seen in many letters sent to the monks in Ceylon.

Pilgrimage
The letter sent by the group of ten senior monks from the Pavaranivesa Temple of Bangkok to the senior monks and others in Ceylon in B.E. 2385 (C.E.1842) mentions that a group of Buddhists, which consisted of four fully ordained monks, namely Saddhātissa, Kakusanda, Vipassi, and Revata; a novice monk named Siddhattha; and two lay people mentioned as the secretary (Lekham) and Band .a, were taken to visit important Buddhist sites, such as the Temple of the Emerald Buddha (Siriratanapat .imāghara), Phra Pathomchedi Temple (Pat .hamamahācetiya), and Wat Phra Phutthabat (Buddhapādalañcanacetiya), and to meet important senior monks, such as the Sangharājā of the Mahānikāya Chapter.They were also brought to temples in ancient cities, such as Saraburi (Salapurī), Suphanburi (Suvannapurī), and Phetchaburi (Vajirapurī) (Buddhadatta 1962, p. 8).
The religious sites in Ceylon that were visited by Siamese monks are also mentioned in several letters.A letter sent by Dhammayuttika monks mentions that the senior monks of the Dhammayuttika sect sent offerings, in the care of six monks who travelled to Ceylon, to be offered at sacred religious sites, namely the Temple of the Tooth (Dhātumandira), Suwannamali Pagoda (Mahāceti), the Sacred Bo Tree (Bodhi), Thuparama Pagoda (Th ūpārāma), Mirisawetiaya Pagoda (Kuntaceti), Sela Chetiya (Selacetiya), the Pagoda at Jetavana Temple (Jetavana), and the Pagoda at Abhayagiri Temple (Abhayagiri) (Bavornnivet 1952, p. 243).
It is evident from many letters that one of the main aims of the travels undertaken by Buddhists from both countries was to visit and worship sacred religious sites in each country.

Conclusions
The cooperation that occurred during this period of time marked a major turning point in the history of Buddhism, as it shaped the form of Buddhism that exists in present-day Thailand and Sri Lanka.It is important to note that only from this period onward has the relationship between the two countries remained unbroken.The newly established Dhammayuttika sect, which was led by Vajirañāna Thera with the support of King Rama III, played a major role in corresponding with the monastics in Ceylon.The close relationships that the Dhamayuttika sect of Thailand had with Sinhalese monks contributed to this sect playing a major role in collecting texts that were not available in Thailand at that time.The senior monks of the Asgiriya and Malwatta Chapters of the Siam sect and the monks of the Burmese sects competitively engaged in corresponding with the monks of Siam.The recognition of the newly established Amarapura and Ramañña sects of Ceylon by the Siamese monks and officials apparently boosted the position of these sects in the Ceylonese Buddhist community.This was not tolerated well by the already-established Siam sect, as they claimed to be the rightful authority.Hence, it is evident from many statements in many of the letters that each sect competed with the other sects in their country to claim the main role in corresponding with the monks in the other country.
Travelling on the merchant ships that connected South and Southeast Asia through maritime routes, Buddhists from both countries exchanged monastic knowledge, historical knowledge, and news through visiting one another, constantly writing letters to each other, and exchanging Buddhist texts that were only available in one of the countries.In order to maintain a cordial relationship, they exchanged gifts and sacred icons in the care of monks who travelled to visit the other country and merchants who sailed for commercial purposes.As Siam was more economically and politically better off than Ceylon during this period, and the ruler of Siam was a patron of Buddhism, whereas Ceylon was under British rule, the Siamese ruler generously provided financial support for these endeavors.The king and senior monks of Siam offered not only financial but also moral support to the monks in Ceylon at this difficult time.The monks of one country not only visited the senior monks and fellow monks in the other country, but they also visited important and sacred religious sites and studied their history, while paying respect accordingly.
In conclusion, the cooperation between Thailand and Sri Lanka during this period was pivotal in solidifying Buddhism in both countries.Through active correspondence, the exchange of texts, mutual visits, and moral and financial support, the Buddhist communities strengthened their ties and enriched their monastic traditions.This enduring collaboration ensured a unified and robust Buddhist heritage that continues to thrive today.
These letters, which are available in the aforementioned publications, have not been thoroughly studied.Therefore, there are still many aspects left to research regarding cooperation between the Buddhists in the two countries, the maritime routes that existed in that period, the political situation of the time, and the sectarian division of the monks.There is great potential for undertaking discourse analysis on each individual letter, as well.