achieved unprecedented levels of internal control and external expansion. They tightened control in the lowlands and reduced the hereditary privileges of Shan chiefs. They also instituted commercial reforms that increased government income and rendered it more predictable. Money economy continued to gain ground. In 1857, the crown inaugurated a full-fledged system of cash taxes and salaries, assisted by the country's first standardised silver coinage. Nonetheless, the extent and pace of reforms were uneven and ultimately proved insufficient to stem the advance of British colonialism. Relations with Siam In 1760, Burma began a series of wars with Siam that would last well into the middle of the 19th century. By 1770, Alaungpaya's heirs had temporarily defeated Siam (1765–1767), subdued much of Laos (1765) and defeated four invasions by Qing China (1765–1769). With the Burmese preoccupied for another two decades by another impending invasion by the Chinese, the Siamese recovered their territories by 1770, and went on to capture Lan Na by 1776. Burma and Siam went to war until 1855 but after decades of war, the two countries exchanged Tenasserim (to Burma) and Lan Na (to Siam). Relations with China In the defence of its realm, the dynasty fought four wars successfully against the Qing dynasty of China which saw the threat of the expansion of Burmese power in the East. In 1770, despite his victory over the Chinese armies, King Hsinbyushin sued for peace with China and concluded a treaty to maintain bilateral trade with the Middle Kingdom which was very important for the dynasty at that time. The Qing dynasty then opened up its markets and restored trading with Burma in 1788 after reconciliation. Thenceforth peaceful and friendly relations prevailed between China and Burma for a long time. Relation with Vietnam In 1823, Burmese emissaries led by George Gibson, who was the son of an English mercenary, arrived in the Vietnamese city of Saigon. The Burmese king Bagyidaw was very keen to conquer Siam and hoped Vietnam might be a useful ally. Vietnam had then just annexed Cambodia. The Vietnamese emperor was Minh Mạng, who had just taken the throne after the death of his father, the founder of the Nguyen dynasty Gia Long. A commercial delegation from Vietnam has recently been in Burma, eager to expand the trade in birds nests (tổ yến). Bagyidaw's interest in sending a return mission however was to secure a military alliance. Relations