This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Asian History. Please check back later for the full article.
Warfare in premodern Southeast Asia was shaped by the environment and political fragmentation across the region. Maritime trade connections saw the introduction and circulation of external models of warfare that would help to frame the way warfare in the region was depicted in indigenous literature and art. Firearms played a more direct role in determining the development of warfare in the region over the course of the early modern period. As a result of the 17th-century crisis and better firearms, the elephant declined in battlefield importance and was increasingly replaced by cavalry. The 18th century saw Southeast Asians field some of their best-organized armies, and the early 19th century witnessed a temporary revival of mainland naval strength. Nevertheless, the introduction of the steamship and better European military technology from the 1820s saw the decline of the remaining Southeast Asian armies by the end of the 19th century. Although indigenous states would attempt to modernize and catch up with Europe militarily, all of Southeast Asia, except for Thailand, fell under European control.