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. The Royal Burmese Army was a major Southeast Asian armed force between the 11th and 13th centuries and between 16th and 19th centuries. It was the premier military force in the 16th century when the Toungoo dynasty built the largest empire in the history of Southeast Asia. The centuries-long warfare between Burma and Siam (1547–1855) shaped not only the history of both countries but also that of mainland Southeast Asia. In the 18th and early 19th centuries, highly militaristic Konbaung kings had built the largest empire in mainland Southeast Asia until they encountered the British in present-day northeast India. Prior to the three Anglo-Burmese wars (1824–1885), previous existential threats to the country had come from China in the form of Mongol invasions (1277–1301) and Manchu invasions (1765–1769). The country was a major battle front in the Southeast Asian theatre of World War II. Since independence in 1948, the country's various political and ethnic factions have been locked in one of the longest civil wars today, with myriad insurgencies receiving implicit and explicit help from various external states. Early history The military history in the early era is sketchy. The Tibeto-Burman-speaking Pyu, the earliest inhabitants of the Irrawaddy valley in recorded history, founded several city states that thrived between the 1st century BCE and the early 9th century CE. In the 8th century CE, Chinese records identify 18 Pyu states throughout the Irrawaddy valley and describe the Pyu as a humane and peaceful people to whom the war was virtually unknown and who wore silk cotton instead of actually silk so that they would not have to kill silkworms. To be sure, this peaceful description by the Chinese was a snapshot of the Pyu realm, and may not represent the life in the city-states in general. The earliest extant record of warfare in the Pyu realm in the early 9th century when the Pyu states came under