Why is Sikkim’s history different from that of other states?

Sikkim was inhabited in prehistoric times by three tribes. They were absorbed by a people known as the Lepcha, who entered Sikkim sometime later. The credit for organizing them into some sort of a society goes to a person called Turve Pa no. Buddhism, the major religion in the state, arrived from Tibet in the 13th century. It took its distinctive Sikkimese form four centuries later, when three Tibetan monks went to Gangtok looking for a certain person whom they crowned as the first Chogyal or ‘Righteous King’ of Denzong in 1642. Being the secular and religious head, he was soon recognized by Tibet, and brought sweeping reforms. After India’s independence, Sikkim became a protectorate of India. The role of India became increasingly crucial, with the Chinese military build-up along the northern borders that culminated in an actual invasion early in the 1960’s. The king, Palden Thondup Namgyal then gave in to the demands of his people, and Sikkim became the 22nd state of India in 1975.