The Sikkim expedition () was an 1888 British military expedition to expel Tibetan forces from Sikkim in present-day northeast India. The roots of the conflict lay in British-Tibetan competition for suzerainty over Sikkim. Causes Sikkim had a long history of relations with Tibet. Buddhism was the state religion and its . In the first half of the 19th century, the British extended their influence to the Himalayas and Sikkim signed the Treaty of Tumlong with the British in 1861. As the British established relations with Nepal, Sikkim and Bhutan, Tibetan influence waned and in Lhasa and Peking it was feared that if left unopposed, the British would encroach into Tibet through Sikkim. Thutob Namgyal, the 9th Chogyal of Sikkim, looked to the Dalai Lama for spiritual leadership and during his reign the Tibetan government started to regain political influence over Sikkim. Under the 1861 treaty, the Chogyal was restricted to spending no more than three months in Tibet but he frequently ignored this provision and in 1887, after having resided for almost two years in Tibet he declined to travel to Darjeeling to meet with the Lieutenant-Governor arguing that the Amban in Lhasa had forbidden him to do so. Meanwhile, he had ordered that the revenue collected be sent to Chumbi, a clear sign of his intention not to return to Sikkim. In 1884 the Indian government prepared to send a diplomatic mission to the Tibetan capital Lhasa to define the spheres of influence of the Tibetan and Indian governments. Colman Macaulay was to be the responsible for the negotiations but the mission was indefinitely postponed after the Tibetan government dispatched an expedition of 300 soldiers that crossed the Jelep La pass and occupied Lingtu around into Sikkim. The British decided to suspend the Macaulay mission since its presence was the Tibetan's argument for their occupation. However, instead of retreating the Tibetans showed every sign of being there to stay. They built a fortified gate on the road that crossed Lingtu coming from Darjeeling and into Tibet, and also constructed a fort for its defence. After negotiations with the Chinese stalled, the Indian government ordered the despatch of a military expedition to Lingtu to restore Indian control of the road. Despatch of the Expedition Starting in 1888, while negotiations carried on the British prepared for a military solution. In January they sent to the frontier the headquarters and one wing