The Burmese–Siamese War of 1849–1855 or Siamese Invasions of Kengtung or Kengtung Wars were military expeditions of the Siamese Rattanakosin Kingdom against the Tai Khün State of Kengtung, which had been under Burmese suzerainty under the Konbaung dynasty. The dynastic struggles in Tai Lue State of Chiang Hung or Sipsongpanna prompted Siam, in cooperation with the Kingdom of Lanna (Northern Thailand), to invade Kengtung in order to gain access to Chiang Hung. In the First Invasion in 1850, the Siamese court had ordered the Lanna Lord of Chiangmai to organize the offensives against Kengtung. Lanna troops failed to conquer Kengtung. Two other expeditions occurred in 1852 and 1853 as Bangkok commanded its troops to directly participate in the invasions. Both expeditions also failed because of