The earliest recorded event related to Sikkim is the passage of the Buddhist saint Guru Rinpoche through the land in the 8th century. The Guru is reported to have blessed the land, introduced Buddhism to Sikkim , and foretells the period of monarchy in the state that would arrive centuries later. In the 14th century, according to legend, Khye Bumsa, a prince from the Minyak House in Kham in Eastern Tibet , had a divine revelation one night instructing him to travel south to seek his fortunes. His descendants were later to form the royal family of Sikkim . In 1642, the fifth generation descendant of Khye Bumsa, Phuntsog Namgyal, was consecrated as the first Chogyal (king) of Sikkim by the three venerated Lamas who came from the north, west and south to Yuksom, marking the beginning of the monarchy.

Phuntsog Namgyal was succeeded in 1670 by his son, Tensung Namgyal, who moved the capital from Yuksom to Rabdentse. In 1700, Sikkim was invaded by the Bhutanese with the help of the half-sister of the Chogyal, who had been denied the throne. The Bhutanese were driven away by the Tibetans, who restored the throne to the Chogyal ten years later. Between 1717 and 1733, the kingdom faced many raids by the Nepalese in the west and Bhutanese in the east, culminating with the destruction of the capital Rabdentse by the Nepalese. In 1791, China sent troops to support Sikkim and defend Tibet against the Gurkhas. Following Nepal 's subsequent defeat, Sikkim became a suzerainty of Qing Dynasty. But Nepal still gained a big piece of land at west of Teesta.

Following the arrival of the British Raj in neighbouring India , Sikkim allied with them against their common enemy, Nepal . The Nepalese attacked Sikkim , overrunning most of the region including the Terai. This prompted the British East India Company to attack Nepal , resulting in the Gurkha War of 1814. Treaties signed between Sikkim and Nepal — the Sugauli Treaty — and Sikkim and British India — Titalia Treaty — returned the territory annexed by the Nepalese to Sikkim in 1817. Ties between Sikkim and the British administrators of India grew sour, however, with the beginning of British taxation of the Morang region. In 1947, a popular vote rejected Sikkim 's joining the Indian Union and Prime Minister Jawaharlal Nehru agreed to a special protectorate status for Sikkim . After a period of unrest in 1972-1973, matters came to a head in 1975, when the Kazi (Prime Minister) appealed to the Indian Parliament for representation and change of Sikkim 's status to a state of India . A referendum was held in which 97.5% of the people voted to join the Indian Union. A few weeks later on May 16, 1975, Sikkim officially became the 22nd state of the Indian Union, and monarchy was abolished. Some still feel that Sikkim is occupied by India , particularly people around the former Royal Family.

Capital : Gangtok
Coordinates : 27.2° N 88.4° E
Largest city : Gangtok
Population (2001) : 540,493
Density : 76.17/km²
Area : 7,096 km²
Districts : 4
Time zone : IST (UTC+ 5:30 )
Official language : Nepali