The Burmese–Siamese War ( 1785–1786 ) , known as the Nine Armies ' Wars in Siamese history because the Burmese came in nine armies , was fought Hostile_encounter between the Konbaung dynasty of Burma and the Chakri dynasty of resurgent Siam ( Thailand ) .

In early 1785 , King Bodawpaya of Konbaung dynasty sent Sending an expedition force to take Conquering Jung Ceylon ( Phuket ) to prevent Preventing_or_letting foreign arms shipments to Siam but the invasion force was driven Motion back .

The war saw the loss Earnings_and_losses of sovereignty of an independent Burma under the Konbaung dynasty , whose rule had already been reduced Cause_change_of_position_on_a_scale to the territory known as Upper Burma , the region of Lower Burma having been annexed by the British in 1853 , as a result of the Second Anglo-Burmese War .