Imphal. The raja of Manipur fled. Hsinbyushin brought back hundreds of Manipuris. The king and his armies arrived back to a newly rebuilt capital of Ava in April 1765. Laotian states (1765) As a first step toward a war with the Siamese, Hsinbyushin decided to secure the northern and eastern flanks of Siam. In January 1765, a 20,000-strong Burmese army led by Ne Myo Thihapate based in Chiang Mai invaded the Laotian states. The Kingdom of Vientiane agreed to become Burmese vassal without a fight. Luang Prabang resisted but Thihapate's forces easily captured the city in March 1765, giving the Burmese complete control of Siam's entire northern border. Siam (1765–1767) The Ayutthaya Kingdom was one of Southeast Asia's most wealthiest and most cosmopolitan polities in the 18th century. Siamese and Burmese interests in the Tenasserim have clashed on and off since the 16th century. For the past 150 years, Burma controlled the Northern Tenasserim ports of Mawlamyine and Tavoy while Siam controlled the Southern Tenasserim ports of Mergui and Tenasserim. Since the Mon revolt of Lower Burma in the 1740s, Ayutthaya had been supporting the Mon rebels in fighting against Upper Burma and the Konbaung dynasts, even after the Konbaung conquest of Lower Burma in 1757. After a number of military incursions into Siam, Konbaung elites noticed that Ayutthaya's armies had not responded quickly to its own military movements on the border with Siam. The invasion of Ayutthaya was, in the words of Chris Baker and Pasuk Phongpaichit, a "joint-stock expedition", designed for the reward of riches of capturing the wealthiest port in Southeast Asia due to the seeming lack of a significant Siamese Army to be able to stop a significant invasion force. After completing the conquest of Laotian states in 1765, Thihapate with his army returned to Lan Na. In the south, Maha Nawrahta's army had also been massing at Tavoy (Dawei), then the border town between Burma and Siam. Thihapate's northern army began the invasion via the Chao Phraya valley in August 1765 during the rainy season. In the middle of October 1765, towards the end of the rainy season, Maha Nawrahta's southern army joined in via Tenasserim for a two-pronged assault. With a policy of total war, Burmese armies captured and sacked most of Ayutthaya's major cities along the way, while most Siamese fled into the jungles. A large number of Siamese soldiers also joined the