After the Second Anglo-Burmese War of 1852, the Burmese kingdom was reduced to Upper Burma alone. The Shan states—especially that east of the Salween River, were essentially autonomous entities, paying token tribute to the king. In 1875, King Mindon, to avoid certain defeat, ceded Karenni states, long part of Shan states, to the British. When the last king of Burma, Thibaw Min, ascended the throne in 1878, the rule of central government was so weak that Thibaw had to send thousands of troops to tame a rebellion in the Shan state of Mongnai and other eastern Shan states for the remainder of his six-year reign.