In the 1870s and 1880s, renewed competition among regional rivals—primarily the pro-British ponlop of Tongsa and the anti-British, pro-Tibetan ponlop of Paro—resulted in the ascendancy of Ugyen Wangchuck, the Ponlop of Tongsa. From his power base in central Bhutan, Ugyen Wangchuck had defeated his political enemies and united the country following several civil wars and rebellions in 1882–85. His victory came at a time of crisis for the central government, however. British power was becoming more extensive to the south, and in the west Tibet had violated its border with Sikkim, incurring British disfavor. After 1,000 years of close ties with Tibet, Bhutan faced the threat of British military power and was forced to make serious geopolitical decisions. The British, seeking to offset potential Russian advances in Lhasa, wanted to open trade relations with Tibet. Ugyen Wangchuck, on the advice of his closest adviser Ugyen Dorji, saw the opportunity to assist the British and in 1903-4 volunteered to accompany a British mission to Lhasa as a mediator. For his services in securing the Anglo-Tibetan Convention of 1904, Ugyen Wangchuck was knighted and thereafter continued to accrue greater power in Bhutan. Ugyen Dorji, as well as his descendants, went on to maintain British favor on behalf of the government from Bhutan House in Kalimpong, India.