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An Examination of the East-West Cultural Corridor

Prof. Mamoru Shibayama Center for Integrated Area Studies, Kyoto University, Japan

Abstract

An aim of this study is to examine the East-West Corridor, which defines as the regional land-based network for trading commodities and cultural exchange from Myanmar to Thailand and Cambodia, with four routes between Myanmar and Thailand on Ishii theory [Ishii 2006, 2008, 2009]. The author mapped and layered the data for these four routes together with the three routes between Cambodia and Thailand in the Royal Road research, the Khmer-style sites in Cambodia and Thailand, and other archaeological sites in Thailand using GIS (Geographical Information System). In addition, the thematic maps showing power relationship in the Indochinese peninsula were added for mapping in order to clarify each route depending on the period behind the Ishii theory.

According to the result of mapping, the author indicates that two routes of Dawei (Tavoy) – Kanchanaburi and Myeik (Mergui) – Phechaburi on mapping data above are coincided with the hypothesis of Ishii theory. Also, this paper describes an individual route for the Angkor, Sukhothai, and Ayutthaya periods derived from the mapping and together with analyzing geological aspect which investigated by geologists Takaya [Takaya 1982] and Somboon [Somboon 1990]. With comparing both routes, the East-West Corridor to the west of the Chao Phraya river system appears to have a very strong relationship in terms of regional road network with Angkor period. The reason for its conclusion is that the extent of Khmer rule and control appears to be related to the ease of access via roads, rivers, and other features. In the Ayutthaya period, a new hypothesis emerged that communities newly built in the area of the ‘paleo-gulf of Ayutthaya (up to around 5,000B.C.)’, it geologically called ‘new delta’ and played important role for trading and exchanging commodities between the coast line of Thai gulf and the hinterland of Ayutthaya. Also, the author discusses the transfer of the capital of Ayutthaya in terms of location and geographical advantage for the rule and control compared with Ishii theory.

1. The East-West Corridor — a land-based culture and trade network Trade with Thailand, China, the Ryukyu kingdom, and Japan has been described from the viewpoint of a Maritime Asia trade network with sea-based routes, but what is the situation regarding a land-based network centered on Thailand? Consider the period when there was intermediate trade by the Ryukyu kingdom as examined in the artcle [Shibayama 2012a], and the period when there were "Shuin-sen" (trading ships licensed by the shogunate) of Japan, followed by trade with China under Japan's subsequent national policy of isolation. Virtually all of these periods coincided with the Ayutthaya dynasty in Thailand. The Sukhothai and early Ayutthaya period was a time of change in Myanmar. From the early 13th century, the power of Bagan waned, and there was a succession of capitals in Upper Myanmar. By the 15th century, Bago (Pegu) near Mawlamyaing (Moulmein) grew stronger [Elizabeth].

Rather than this period, the present report considers periods that were a little earlier, introducing cultural and trade networks in and around Thailand from about the 10th century, to the Sukhothai dynasty (13th century-15th century), and Ayutthaya dynasty (15th century-18th century). Particular attention is paid to the East-West Corridor in the 11th century-14th century, focusing on Bay of Bengal-Sukhothai trade routes, the Royal Roads around Angkor, and trade routes from Tenasserim in southern Myanmar to Ayutthaya [Shibayama 2012b]. The term "East-West Corridor" is also used for an economic corridor in today's Indochinese peninsula, largely in Thailand [Kakizaki 2011], but that is beyond the scope of this paper.

Regarding references concerning the East-West Corridor, in "Tonan Asia shi no teisetsu wo saikento suru" (Re-examining established theory in Southeast Asian history) [Ishii 2006] and "'Tozai kairo' ni kansuru oboegaki" (A note on the East-West corridor) [Ishii 2009] Ishii sets out a hypothesis regarding trade routes from Myanmar to Thailand at the time of the Sukhothai dynasty. His hypothesis includes a description of trade routes crossing central Thailand to reach Angkor in Cambodia, and then linking to the Maritime Asia network via the Mekong Delta in southern

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Vietnam. In addition, research conducted over a hundred years ago by and in association with the École française d'Extrême-Orient (EFEO) posited that there were two Royal Roads from Angkor linking with Thailand. Furthermore, a Thailand-Cambodia joint project is currently working on digs to survey a route between Angkor and Phimai (Nakorn Ratchasima, Thailand). Sakurai is surveying a route from Angkor to Aranyaprathet in Thailand, a further route between Angkor and Thailand, and investigating the history of the Khmer Empire (9th century-13th century)[Sakurai 2012]. Also, the author introduced the regional routes from Myanmar to Thailand [Shibayama 2012].

The author mapped both the Ishii theory and the Sakurai theory in the GIS to obtain an overview. In addition, 52 thematic maps indicating the extent of rule and control by different powers in the Indochinese peninsula from the 2th century to the 16th century [TimeMap Project 2003], the Thailand-Cambodia joint project's list of around 2,770 sites in Thailand provided by the Living Angkor Road Project1 (hereafter, it called LARP project), and a list of about 380 Khmer-style sites, which was listed mainly focused on Thailand by the author, were all mapped and layered in the GIS in order to search out East-West Corridor trade and communication routes. 1-1. East-West Corridor passing through Sukhothai In debate over the existence of the East-West Corridor, Ishii started by referring to how Thailand's historical periods are divided. Until now, researchers have viewed Thailand's history from a linear perspective, designating the Sukhothai period (13th-14th century), Ayutthaya period (14th-18th century), Thonburi period (18th century), and Bangkok period (18th century-the present). However, Ishii asserted that instead of taking this sort of linear perspective, it was important to think in terms of three categories, (a) Shan cultural area or Lanna, (b) Mueang Nua (northern states), (c) maritime city states along the Thai coast, and to take an overview of the political, cultural, and trade relationships between them [Ishii 2006]. From that background, and based on Sukhothai stone inscription No.1 (1292.A.D.), Ishii theorized that an East-West Corridor passed through Sukhothai, with a route between Myanmar and Sukhothai going from Martaban in Myanmar via Moulmein, Kawkareik, and Kyondo, and then Mae Sot in Thailand to Tak, and Sukhothai. Items traded included elephants, horses, and gold & silvers.

Figure 1. Sukhothai period trade route Figure 2. The East-West Corridor on the hypothesis [Source: Ishii 2008] by Ishii and Sakurai

The route is shown in Figure 1. Figure 2 shows the hypothesis of the East-West Corridor and Royal Road mapped by the GIS onto maps showing the Khmer-style sites in the Angkor period from the time of Suryavarman II to Jayavarman VII. From the Angkor period to the time of the rise of the Sukhothai dynasty in Thailand, trading occurred along with the transmission of Mahayana Buddhism and Theravada Buddhism from India and Sri Lanka. Evidence to support this includes the presence of Khmer-style sites distributed in Thailand, and the excavation or discovery of structures, artifacts, and other archaeological findings along the trade route, such as hospitals, rest houses, bridges, iron foundries, salt production, and ceramics.

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Ishii also described a pilgrimage route referenced in Sukhothai stone inscription No.11 (1350.A.D.), which tells of how the priest Mahathera Srisraddharajaculamuni, who had been training in northern Thailand, went to Sri Lanka, taking a route from Uttaradit via Lamphun near Chiang Mai, and then returned to Phitsanulok several years later. The Mahathera traveled from Lamphun to Tak, crossed into Myanmar from Mae Sot, then took the route to the Bay of Bengal that will be described below. After spending two years in Sri Lanka, he came back to Tenasserim from Mergui, one of Myanmar's maritime city states. From Tenasserim, he crossed the Maw Daung Pass to Prachuap Khiri Kan in Thailand, then reached Phetchaburi. From there, he traveled via Ratchaburi, Suphan Buri, and Ayutthaya to arrive back in Phitsanulok.

Figure 3. The Mahathera's pilgrimage route Figure 4. Four trade routes to the bay of Sukhothai stone inscription Bengal/Andaman sea No.11 (1350.A.D.)

Figure 3 shows the result of mapping the routes described on Sukhothai stone inscription No.11 into the GIS. Ishii concludes that the four routes shown in Figure 4 existed from the Sukhothai dynasty to the early part of the Ayutthaya dynasty((1) Martaban—Moulmein—Mae Sot—Sukhothai, (2) Dawei (Tavoy)—Bon Ti—Kanchanaburi, (3) Myeik (Mergui)—Tenasserim—Dan Sing Khon—Prachuap Khiri Kan—Phetchaburi, (4) Phuket—Nakhon Si Thammarat).

(1) Myanmar-Thailand border (2) Sangklaburi immigration office (taken from the Thailand side) at Thai border post

Figure 5. Likely border crossing point in the Ayutthaya period [Photos taken by author on August 28, 2012.]

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In fact, surveys of historical sites by the Fine Arts Department, Ministry of Culture, Thailand have discovered Khmer-style sites and artifacts at Si Thep, located between Lop Buri and Phitsanulok, so it is known that there was a trade route. In Figure 5, the second route from the top is a corridor running on the Thailand side from Lopburi, Suphan Buri, and Kanchanaburi to Myanmar. Figure 5 shows photos taken by the author at the border crossing on this route. 1-2. Royal Road runs in five directions from Angkor Returning to the situation in the Angkor period set out in Figure 2, archaeologists have been researching the Royal Road for over a century. Evidence for the route includes the Preah Khan stone inscription (1191.A.D.) and others. Recently, the LARP project has researched the road from Angkor to Phimai in Thailand, discovering and surveying villages located several hundred meters away from the main route that were involved in the production of iron, salt, or laterite. Figure 6 shows the routes taken by the Royal Road from Angkor in Cambodia. The Royal Road can be described as having three principal routes: (1) A route from Angkor to Aranyaprathet in Thailand [Route A], (2) A route from Angkor to Phimai [Route B], and (3) A route from Angkor passing to the south of the well-known historical site at Preah Vihear, then continuing to Wat Phu in southern Laos [Route C].

Figure 6. Royal Road around Angkor Figure 7. Khmer Empire and Khmer-style sites [Source: Bruno Bruguier 2000, BEFEO] (Red dots and inside of red poly-line)

In Figure 7, the Royal Road is overlaid in the GIS with the locations of approximately 380 Khmer-style sites. By combining this information, you can see that a large number of Khmer-style sites are situated near to the ends of Royal Road ‘Route A’ and ‘Route B’. The base for this map is a current vector map of the Indochinese peninsula in the GIS. As described above, the author has added a number of layers to the map to show the extent of the Khmer Empire using 52 thematic maps showing the extent of rule or control (provided by Prof. Roland Fletcher of the University of Sydney), a number of examples of the East-West Corridor based on the Ishii theory, Royal Road ‘Route A’ according to the Sakurai hypothesis, Royal Road ‘Route B’ according to the LARP project, and also the locations of some 380 Khmer sites. The contemporaneous kingdoms in Myanmar (Burma) are also mapped. Furthermore, to incorporate information about Hoshino's sema culture[Hoshino 1990], the sema stones used to mark the boundaries of the space for Theravada Buddhism ordination ceremonies are also mapped in the GIS. This map also shows that there are Khmer-style sites at locations outside the area controlled by the Khmer Empire based on the map derived from the TimeMap Project. This is new findings on GIS-based study. 2. What can be seen from the GIS mapping The data listed above was insufficient for an investigation of the East-West Corridor centered on Thailand. As a subsequent step, the author took the data on about 2,770 historical sites in Thailand obtained from the LARP project and entered it into the GIS. It must be remembered that since the GIS handles spatial data, the process of incorporating information into the GIS

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requires clear latitude/longitude data for each item before it can be mapped and incorporated into the GIS map. The latitude/longitude data was added to data for the four routes between Myanmar and Thailand listed in the context of the East-West Corridor, the three routes from the findings of Royal Road research, and also for approximately 380 Khmer sites, and approximately 2,770 sites within Thailand. Latitude/longitude data was also clarified with rectifying all the 52 maps showing power relationships in the Indochinese peninsula.

The point data for these maps and historical sites, and the line data showing the East-West Corridor was all layered onto the base map. The result, omitting only the sema culture information, is shown in Figure 8.

Figure 8. Information on the East-West Corridor, Royal Road, Khmer sites, sites within Thailand, and Burmese kingdoms layered onto a map

of power relationships of the Khmer Empire [Base Map: Fletcher 2003] Having mapped all this information into the GIS, the next step is to examine what emerges. 2-1. Regional Road in the Angkor Period (1) The form of the East-West Corridor emerged along with the rule and control of the Mons and Khmers, and with the rise and fall of the Sukhothai Kingdom and Ayutthaya Kingdom. In particular, the East-West Corridor emerged strongly with the rise of the Sukhothai Kingdom. In contrast, when the arrangements and forms of sites in the preceding Angkor period are mapped in time and space, contemporaneous trade routes from the Royal Road to the regions emerge. Conventionally, researchers have to take the various phenomena emerging from historical descriptions and bring them together in their own minds to sort out and evaluate the information. That process was not always accurate, and was prone to omitting or not noticing information. Currently, research in collaboration with Thai researchers is in progress to investigate predominantly the routes for the Khmer-style sites. From the mapping achieved to date, the routes emerging are much like those shown in Figure 8.

The East-West Corridor shown in Figure 8 depicts nearly all the main routes and regional routes for communication and trade from the 11th century to the 14th century. Note, however, that the different routes actually existed at different times, so further analysis incorporating a time axis is still required.

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Recent surveys by the Fine Arts Department, Thailand have shown that the route from Phitsanulok to Si Thep in Figure 9 was actually a river route using the Pasak River, and there is not yet sufficient evidence to confirm the route from Phimai to Si Thep. That confirmation will have to wait for subsequent surveys.

Figure 9. An estimated regional road in the Angkor period (2) The locations of the Khmer-style sites extend further than the rule and control of the Khmer Empire in the Indochinese peninsula power relationships map where the empire controls the largest area (the map for 1181-1219). Wat Phra Si Rattana Mahathat in Si Satchanalai, Sukhothai Province (in reign of Jayavalman VII, 1181-1219.A.D.) is a representative example. This observation has to be interpreted as indicating that the Indochinese peninsula power relationships maps have been drawn in the basis of reference materials, and the areas depicted in the maps have been determined with reference to today's national boundaries, but that the results are inconsistent with reality. In fact, controlling power does not extend uniformly over an area. In contrast, the proper way to determine the extent of such relationships is probably to consider routes based on topography and environment, since it is features such as roads, rivers, and the presence of local villages that determine how easily ethnic groups can move.

Figure 10. Sri Thep Khmer-style sites Figure 11. Kanchanaburi Khmer-style site

Wat Prasat Mueang Sing [Photo taken by author on 29th August, 2012]

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(3) A new hypothesis emerges: A route from Si Thep to Lopburi, Suphan Buri, and close to Ayutthaya has made a very large contribution to trade. In particular, there are Khmer-style sites from Phetchaburi (near the resort of Hua Hin) to Suphan Buri, Lopburi, and Kanchanaburi, and there is evidence to demonstrate such a route, but it is very interesting to note how the routes have changed over time. Also, these areas all have major river systems, and manufacturing sites for Thai ceramics are distributed throughout the same areas.

(1) Aerial photograph taken in 1945 (WHC2) (2) Khmer-style sites today [Photo taken by author on 4th October, 2012]

Figure 12. Lop Buri Khmer-style site (Wat Phra Si Maha That) Figure 10 shows a Khmer-style site at Si Thep, and Mon sites are visible only a few hundred meters away. Figure 11 is on the route from Dawei (Tavoy) in Myanmar to Kanchanaburi that might be linked to the border crossing point on Ishii theory as shown in (2) of Figure 4. Figure 12 shows a site in Lop Buri which was probably established in the 12th-13th Buddhist centuries and was Khmer art and Bayon style (the Fine Arts Department). It is an extremely important location when considering trade routes. 2-2. Regional Roads in Sukhothai and Ayutthaya Periods Next, the author investigates a distribution of archaeological sites in the Sukhothai and Ayutthaya periods using the GIS. The source data for mapping is Sukhothai 189 and Ayutthaya 827 sites derived from about 2,770 historical sites in Thailand. The result of mapping is shown in Figure 13. What can be seen from the result is described as below.

First, the regional road in the Sukhothai period on Ishii theory coincided with the site mapping. And, in the Ayutthaya period, the regional road which runs six directions from Ayutthaya emerged on GIS analysis. By looking at it with clockwise from the lower left, (a)Southwest route from Ayutthaya to Phetchaburi, (b) West route from Ayutthaya to Suphanburi and Kanchanaburi, (c)North route from Ayutthaya to Si Thep and Phitsanulok, (d) Northeast route from Ayutthaya to Nakhorn Ratchasima via Lopburi, (e)East route from Ayutthaya to Nakhorn Nayok, Chaochensao, and Chonburi, and (f) South route from Ayutthaya to Phathum Thani, Nonthaburi, and Bangkok.

In Figure 13, the buffer zone with a radius of 10 and 20 kilometers for the Sukhothai period and 10 kilometers for the Ayutthaya period at the center of each site is displayed using one of functions in GIS. An estimated route can be seen on the analysis of buffering with relationship between the data of archaeological sites. Mainly, two characteristics are emerged from the mapping. First, a route of Dawei [Tavoy], Bon Ti, and Kanchanaburi on the Ishii theory mostly coincides with the mapping except the border crossing point at Sangklaburi (see Figure 5) as shown in Figure 13(2).

Second, Many sites between Phatamthani, Nontaburi, and Bangkok in the south route can be seen, in other words, appeared compared with Angkor and Dvaravati periods. Why ruins were not existed in this area before? It is important to explore this reason. The author estimates that

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topographical change in progress of forming new delta in Chao Phraya delta might be affected to establish new communities and a place of residence. The discussion followed by next section.

(1) The regional road in the Sukhothai period

(2) The regional road in the Ayutthaya period

Figure 13. An estimated regional roads in Sukhothai and Ayutthaya periods

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3. Consideration An aim of this study is to examine the East-West Corridor discussed on Ishii’s hypothesis that four routes from Myanmar to Thailand as the trading route were existed and it linked to the Royal Road from Cambodia to Thailand and Laos. In order to examine his hypothesis and to lead a new hypothesis behind his discussions, the author mapped and layered the data for the four routes between Myanmar and Thailand listed in the context of the East-West Corridor, the three routes from the findings of Royal Road research, and also for approximately 380 Khmer sites, and approximately 2,770 sites within Thailand. Latitude/longitude data was also clarified for all the 52 maps showing power relationships in the Indochinese peninsula. One of discussions which derived from above mapping is how Khmer Empire controlled and expanded their rule and network in Thailand. It is considered that, as mentioned above, the East-West Corridor and Khmer’s domination have much deeper relationship in terms of the cultural or commodity exchange and control between both. In fact, controlling power does not extend uniformly over an area. In contrast, the proper way to determine the extent of such relationships is probably to consider routes based on topography and environment, since it is features such as roads, rivers, and the presence of local villages that determine how easily ethnic groups can move. Based on these considerations, it is considered that ancient places of the Khmer style in the 12-13th centuries played the role of node for networking their control. In other words, places were probably nodes of the East-West Corridor or the land marks for finding appropriate location in the road by the people. Therefore, mapping for showing the extent of the Khmer Empire by Fletcher must have wrongly done in terms of way of mapping in the informatics methodology. Evidences can be seen through the fact of several Khmer style sites were obviously existed behind the extent of Khmer Empire showing by the thematic map in Angkor period. Moreover, southern area from Ayutthaya was ‘paleo-gulf of Ayutthaya’ and newly formed delta before the Ayutthaya period. This means that it was not used as the living area or agricultural field in those days [Pramojanee]. So, drawing map for Angkor period depending on only current topographic features must be wrong way for mapping. This issue is followed by next discussion. Next discussion is to clarify a route compared with Ishii’s hypothesis from Ayutthaya to Kanchanaburi through Suphanburi within six directions as shown in Figure 13. This mapping clearly showed to back up his theory except at the border crossing point in Sangklaburi. A part of the route was once used as the rail-way between Thai-Burma under the period of Japanese rule. From the mapping of Khmer style sites, Wat Prasat Mueang Sing as shown in Figure 11 is located on the route. The result showed that the route from Kanchanaburi might be reached to Burma. However, no evidences were cleared. Also, the border between Ayutthaya and Burma in the Ayutthaya period must have known at Sangkhraburi as shown in Figure 13(2).

(1) Angkor period (Thavarawadi and Lop Buri sites are included)

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(2) Sukhothai Period (the red line shows an estimated road by Ishii theory except a route (2) in Figure 4)

(3) Ayutthaya Period (red lines show the estimated road by Ishii theory) Figure 14. Comparison of Regional Roads between the Angkor, Sukhothai, and Ayutthaya Periods

(the gray colored area shows ‘new delta’ between the Thai gulf and Ayutthaya) Most interesting discussion is in the Ayutthaya period focusing on a route from Ayutthaya to Nonthaburi and Bangkok through Chao Phraya River. This discussion occurs from relative comparison between three figures, (1), (2), and (3) in Figure 14. Why no archaeological sites were existed in the periods such as Dvaravati, Angkor, and Sukhothai before Ayutthaya as shown in Figure 14. Its sufficient grounds can be derived from discussions by both geologist Takaya and Somboon. And, it is delivered of a new hypothesis.

Takaya explained an area classification in the Chao Phraya Delta on the geological and landscape surveys [Takaya 1982, 2012]. He defined the area from coast of Thai gulf to Ayutthaya as a ‘new delta’ and ‘old delta’ reaches Chainut behind Ayutthaya. According to Takaya theory, it has to be considered that when new delta was formed and how delta was expanded. Somboon gave a new theory that the expansion of new delta was started from around 5,000B.C. and the southern area from Ayutthaya was ‘paleo-gulf of Ayutthaya’ as shown in Figure 15.

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Figure 15. The ‘Paleo-gulf of Ayutthaya’ in 5,000B.C. [Source: Somboon 1990]

Namely, it means Bangkok, Notaburi, and Pathum Thani in southern part from Ayutthaya were under the sea in those days. Pramojanee also estimated that current coast line was formed in around 450A.D. [Pramojanee] Therefore, new cultivation of land and living area were impossible in new delta. This explanation coincides with the criticism on the landscape survey by Takaya. Eventually, it can say that new villages and cultivated land were formed on the natural bank in the new delta after transferring the capital to Ayutthaya. Such understanding can be seen in Figure 14. The author estimates old cities along with ‘paleo-gulf of Ayutthaya’ and new cities on the natural bank played important role for trading in the Ayutthaya period in the East-West Corridor on Ishii theory as well. 4. Conclusion In this paper, an aim of this study is to examine the East-West Corridor discussed on Ishii’s hypothesis that four routes from Myanmar to Thailand. Such routes are as follows; (1) Martaban—Moulmein—Mae Sot—Sukhothai, (2) Dawei (Tavoy)—Bon Ti—Kanchanaburi, (3) Myeik (Mergui)—Tenasserim—Dan Sing Khon—Prachuap Khiri Kan—Phetchaburi, (4) Phuket—Nakhon Si Thammarat. The routes (1) and (3) are explained in the Sukhothai period, and the routes (2) and (3) are explained in Ayutthaya period respectively in the Ishii theory. It can be considered that the East-West Corridor was existed as the trading and cultural exchange network. The author mapped and layered the data for above four routes, the three routes, which includes roads in Cambodia from the findings of Royal Road research, and also for approximately 380 Khmer sites, and approximately 2,770 sites within Thailand. Latitude/longitude data was also clarified for all the 52 maps showing power relationships in the Indochinese peninsula in order to clarify each route depending on the period behind the Ishii theory.

As the author has stated before, the East-West Corridor to the west of the Chao Phraya river system in Thailand appears to have a very strong relationship with Khmer-style sites. The reason for that conclusion is that, as described above, the extent of Khmer rule and control appears to be related to the ease of access via roads, rivers, and other features. Especially, this paper discussed individual route for Angkor and Ayutthaya periods derived from the mapping. With comparing both routes, it can be considered that many villages and cultivated lands were appeared on the natural bank in the area of ‘paleo-gulf of Ayutthaya’ after starting the rule of Ayutthaya. It reason has been supported on studies of geological and archaeological analyses by Takaya, Somboon, and Pramojanee. According to the mapping and analyses, new hypothesis emerged that communities as mentioned above newly built in the area of the ‘paleo-gulf of Ayutthaya’ and played important role for trading and exchanging commodities between the coast line of Thai gulf and the hinterland of Ayutthaya. The discussion of transferring

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the capital of Ayutthaya in terms of location and advantage for ruling by Ishii theory might be affected by this result.

The points set out above are the main points discovered through mapping in the GIS. For the 380 Khmer sites and the 2,770 sites within Thailand, further work is required to conduct analysis on a time axis as done for the Maritime Asia network, and in conjunction, to perform spatial mapping for these items. Acknowledgement The author would like to express his sincere gratitude to Dr. Surat Lertlum, Chulachomklao Royal Military Academy of Thailand, Prof. Surapol Natapintu, The Thai Research Fund, Mr. Im Sokrithy, APSARA Authority ,Siem Reap, Cambodia, Mr. Pongdhan Sampaongern, Si Thep Historical Park, Fine Arts Department, Thailand, and Dr. Elizabeth Howard Moore, SOAS, University of London, U.K. who gave him various criticism and fruitful discussions. Notes 1. LARP: Living Ancient Road from Angkor to Phimai Project. This project to research the Thailand Royal Road was conducted from 2004 to 2009 in collaboration with Cambodia APSARA (Authority for the Protection and Management of Angkor and the Region of Siem Reap), with funding from the Thailand Research Fund. Project leader was Dr. Surat Lertlum (Chulachom Krao Royal Military Academy). 2. WHC: Williams-Hunt Collection. Collection of aerial photographs of Indochina and Southeast Asian islands taken by Peter Williams-Hunt (U.K.) over several years beginning in 1944. The collection is currently housed in locations that include SOAS at London University, the Center for Southeast Asian Studies, Kyoto University (CSEAS), and Singapore. CSEAS holds approximately 5,000 photographs from the collection. References [1] Shibayama, Mamoru. 2012a. "Chiiki joho mappinngu kara yomu tonan Ajia" (Reading Southeast Asia from Area Information Mapping), Bensei. [2] Shibayama, Mamoru. 2012b. "In Search of East-West Corridor by Japanese Scholars: Geoinformatics and Cultural Regions," Workshop on Studies along the East-West Cultural Corridor, Field School of Archaeology (FSA), Pyay, Myanmar, 21st August. [3] Kakizaki, Ichiro. 2011. “Tonan Ajia wo manabou” (Let’s learn Southeast Asia), Chikuma. [4] Ishii, Yoneo. 2006."Tonan Asia shi no teisetsu wo saikento suru" (Re-examining established theory in Southeast Asian history), Japan Society for Southeast Asian Archeology Monograph No.4, Japan Society for Southeast Asian Archaeology, pp.1-7. [5] Ishii, Yoneo. 2008. "History and Environment," Handout in Workshop on Area Informatics, Center for Southeast Asian Studies, Kyoto University. [6] Ishii, Yoneo. 2009. "Sukhothai wo tsuka suru 'tozai kairo' ni kansuru oboegaki" (A note on the East-West corridor passing through Sukhothai), published in Tonan Asia: Rekishito Bunka (Southeast Asia: History and Culture), No.38, pp.5-12. [7] TimeMap Project. 2003. “Animated TimeMap of the Khmer Empire 100 CE - 1550 CE”, University of Sydney, Australia. http://www.timemap.net/. [8] Ishii, Yoneo. 1991. "Six Hundred Years of Thai-Japan Relationship" in Tai kinseishi kenkyuu josetsu (Collected Papers on the Early Modern History of Siam), Iwanami Shoten, pp.48-66. [9] Ishii, Yoneo and Toshiharu Yoshikawa. 1987. "Six Hundred Years of Thai-Japan Relationship," Kodansha. [10] Sakurai, Yumio. 2012. "Histoire de La Voie Royale Angkorienne," Handout in Seminar at Kyoto University Center for Southeast Asian Studies Bangkok Liaison Office, June. [11] Hoshino, Tatsuo. 1990. "Dakuryu to mangetsu: Tai minzokushi e no shotai" (Muddy Stream and Full Moon: Invitation to the History of Ethnic Groups in Thailand), Kobundo. [12] Lertlum, Surat and Shibayama, Mamoru. 2009.: Application of Geo-Informatics for Cultural Studies in the Southeast Asia: Royal Road from Angkor to Phimai, Journal of Southeast Asian Studies, Vol.46, No.4, 541-553, 2009 [13] Pramojanee. P., and Jarupongsakul. T., Evolution of landforms and the Sites of Ancient Cities and Communities in Lowr Chao Phraya Plain. [14] Somboon, JaRuPongsakul. 1990.”Geomorphology of The Chao Phraya Delata, Thailand”, Doctoral Thesis, Kyoto University. [15] Takaya, Yoshikazu. 1982. “Agricultural Evolution in the Tropical Delta: The Case of the Menam Chao Phraya Delta”, Tonan-Ajia Kenkyu-Sosho(Japanese), Sobunsha. [16] Takaya, Yoshikazu. 2012. “Field Note Collection 3”, CIAS Discussion Paper No.22 (Japanese), Center for Integrated Area Studies, Kyoto University.

(31th January 2013)