Abstract:
This study investigates the history of diplomatic relations between Siam and Vietnam from the late eighteenth century to the early nineteenth century. Based on Vietnamese and Thai primary sources and other related sources, the thesis mainly examines activities between states. This period carries great significance in the major historical shifts in mainland Southeast Asia. However, due to lack of sources in both languages and the difficulty in accessing Vietnamese sources, in particular, as well as limitations due to language barriers in general, it remains understudied. The old prosperous kingdoms of Ava and Ayutthaya were in declined and collapsed from war and chaos. In Vietnam, the war between the Nguyễn and the Trịnh family emerged while the Lê emperor became powerless. The rise of new kingdoms including the Alaungpaya Dynasty in Burma, Thonburi and Chakri Dynasties in Siam, and the Nguyễn Dynasty in Vietnam, later on brought about significant interactions between these states. This involved not only trade and warfare, but also continuous power struggle in mainland Southeast Asia. Previous studies have yet to thoroughly investigate these interactions, especially the contestation between Siam and Vietnam (the Nguyễn Lords). Their relations started in the late Ayutthaya period, escalated to severe confrontation in the Thonburi era, and reverted to amity during the first two reigns of the Chakri Dynasty. These shifted relations emerged from many factors. Moreover, Siamese-Vietnamese relations during this period also had significant impact on Siams relations with states further East in the following period.