once more. But this time, with relations with Britain stable, the Burmese were ready. Mindon had deployed a larger, well-equipped army (with artillery corps and 3,000 cavalry). The Siamese forces again reached Kengtung but could not break through. The Siamese forces withdrew to the border in May 1855. Karenni states (1875) In the early 1870s, the British again established designs on Burmese territories north, this time, the Karenni states, which were the southernmost part of the Shan states, and ruled by its hereditary Shan sawbwas. In 1873, Mindon had to send troops to quell a British-supported rebellion. The British were adamant, demanding that Mandalay recognise the independence of the Karenni states, and that anything less would be deemed an act of war. Facing a certain defeat, the king chose to refrain from suppressing their independence and signed away the territory in March 1875. Per treaty, the Burmese troops withdrew from the territory but the British troops remained in the newly independent territory, causing Mindon to lose considerable prestige at home. The British would eventually drop their insistence that the Karenni states were independent in 1892, after the conclusion of the Third Anglo-Burmese War. Shan states rebellions (1878–1885) In October 1878, Thibaw, a junior prince, succeeded the throne, and soon proved an ineffectual king. His authority quickly waned, especially in the hill regions, which had paid nominal tribute even during his father's reign. Indeed, Mindon had held on to the fealty of Shan states not by force but by maintaining personal relationships. But Thibaw did not command any respect. The Shan state of Mone first revolted, refusing to attend the king's coronation. Soon, the rebellion spread eastward. For six years, thousands of Thibaw's troops were sent to put down the revolt, "trying in vain to resurrect a long-dead empire". Third Anglo-Burmese War (1885) In 1885, the British sought to annex the rest of the kingdom. They had been concerned by the Burmese efforts to form an alliance with the French, who were consolidating their holdings in nearby French Indochina. Burma was trying to pursue the same strategy as Siam, as a buffer between the British and the French. But the British viewed Burma as their sphere of influence, and sent in an expeditionary force on 7 November 1885. The British easily overcame minimal Burmese resistance, and captured Mandalay on 29 November 1885. The Burmese king Thibaw and the royal family were