Pegu was a kingdom in the south of OTL Burma. Originally a part of Pagan, when in the 1430s: Inner conflicts in Pagan split the country in two halfs. One of them, the Pegu dynasty (from the city with the same name), asked Hong China for help, gaining control of the rest of OTL Burma. China's sphere of influence now borders India.
1638 (3335, Yang Earth Tiger in the Chinese calendar), the ruler of Pegu started an intrigue at the Hong court against Ayutthaya, gaining the emperor's favor. Pegu annexed a border province some years later.
1774, Pegu invaded N Burma, where they met Chinese troops and (more or less) surprisingly defeated them.
In 1776 (which was after French influence had ceased as France became a republic) Italy sent diplomats to Pegu, establishing a trade treaty.