The military history of Myanmar (Burma) spans over a millennium, and is one of the main factors that have shaped the history of the country, and to a certain degree, the history of Southeast Asia. At various times in history, successive Burmese kingdoms were also involved in warfare against their neighbouring states in the surrounding regions of modern Burmese borders—from Bengal, Manipur and Assam in the west, to Yunnan (the southern China) in the northeast, to Laos and Siam in the east and southeast.