sikkim was rules by namgyal-chogyal dynasty from 1642 to 1975 and was a buddhist kingdom under them. initially the capital was yuksom and then shifted to rabdentse towards the end of 17^th century. prior to this, sikkim was inhabited by lepcha tribe who were mainly farmers. sikkim always faced the threat from nepal and had time and again had to defend itself from them.

darjeeling which was a part of sikkim, in 1835 was annexed by british india. sikkim was a protectorate first of british india where under the titallia treaty between british and sikkim, the former guaranteed sovereignty  and independence of sikkim. after india’s independence in 1947, it became a protectorate of india where british passed on the guarantee to india. infact in december 1950, by signing “india-sikkim peace treaty”, sikkim official became india’s protectorate.

in april 1973, india took control of sikkim as its associate state as the people overthrew the monarchy. on april 9, 1975, the sikkim parliament announced the king was deposed and declared sikkim had become part of india through a referendum. finally on 16^th may 1975 parliament of india declared that sikkim had officially become a part of india and its 22^nd state.