The Anglo-Tibetan War of 1888 starts.

The Sikkim expedition was an 1888 British military expedition to expel Tibetan forces from Sikkim in present-day north east India. The roots of the conflict lay in British-Tibetan competition for sovereignty over Sikkim.Sikkim had a long history of relations with Tibet. Buddhism was the state religion and its Chogyal rulers were descended from Shabdrung Ngawang Namgyal, a Tibetan saint who unified Bhutan. 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.
The 13th Dalai Lama with Thutob Namgyal in Darjeeling, ca.

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 13 miles 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.