He then marched south and reestablished Siamese rule over the Malay Peninsula as far as Penang and Terengganu. Having secured his base in Siam, Taksin attacked the Burmese in the north in 1774 and captured Chiang Mai in 1776, permanently uniting Siam and Lanna. Taksin's leading general in this campaign was Thong Duang, known by the title "Chaophraya" or Lord Chakri was himself a descendant of Mon people. In 1778 Chakri led a Siamese army which captured Vientiane, also Luang Phrabang, a northern Lao kingdom submitted, and eventually established Siamese domination over Laotian kingdoms.