Sikkim, a mountainous state, owes its modern origin way back in 1642 A.D. when its kingdom was ruled by its first monarch Phuntsog Namgyal who was consecrated as the first king of Sikkim by three monks: Lhatsun Chhenpo, Nga-Dag Lama and Kathog Lama at Yuksam in western Sikkim. At that time, the territory of Sikkim was extended up to Limbuwan in the west, Chumbi Valley and parts of Bhutan in the east and the entire Darjeeling district in south. The capital of the state was Yuksam. The then king divided the state into twelve dzongs (district), placed each under a lepcha dzongpan (governor) for centralized administration.
In the next generation, the king Tensung Namgyal, moved the capital to Rabdentse in 1670 A.D. for security reasons. After a long gap, Tsudphud Namgyal, a king of the same dynasty, shifted the capital to Tumlong in 1814 A.D., as Rabdentse was considered to be too close to Nepal. During the period of Thutob Namgyal, the capital of Sikkim was again shifted in 1894 A.D. to Gangtok and since then it remained as the capital. As per the treaty of India and Sikkim, which was signed in 1950, the Indian Government took over the administration of the Sikkim. However, the Namgyal dynasty continued till the Sikkim acquired full democracy and become the 22nd state of Indian Union on 16th May, 1975.
The state is situated between 27°04' 46" and 28°07' 48" north latitudes and 88°00'58" and 88°55'25" east longitudes. The state is extending approximately 114 km from north to south and 64 km from east to west having total geographical area of 7,096 sq km. Rivers and mountains define the boundaries of Sikkim. The state shares its southern boundary, which is delineated by Rangit and other rivers, with Darjeeling district of West Bengal. Three sovereign nations, the kingdom of Nepal in the west, Bhutan in the east and vast stretches of Tibetan plateau of China in the north bound the state. » Read More
Natural Resources Atlas of Sikkim - (Source: NATMO, Kolkata)