With Burma preoccupied by the Chinese threat, Ayutthaya recovered its territories by 1770, and went on to capture Lan Na by <answer>1776.</answer> Burma and Siam went to war until 1855, but all resulted in a stalemate, exchanging Tenasserim (to Burma) and Lan Na (to Ayutthaya). Faced with a powerful China and a resurgent Ayutthaya in the east, King Bodawpaya turned west, acquiring Arakan (1785), Manipur (1814) and Assam (1817). It was the second-largest empire in Burmese history but also one with a long ill-defined border with British India.
In what year did  Ayutthaya capture Lan Na  ?
1776.