Bhutan introduced its first postage stamps in 1962 (10th October) and in its inaugural issue it featured seven definitive stamps on different denominations. The first stamp series featured the introduction of Bhutan life style. One of the stamps released finds a special place among the stamp collectors of Sikkim. Sikkim, though once an independent country is today a proud part of Indian Union. Sikkim became part of India in 1975.
The 15ch postage stamp issued from the country of Bhutan is probably the only postage stamps in the world of philately that showed Sikkim as an Independent Country. You can closely see an Independent Sikkim, below it India while East Pakistan now Bangladesh just beneath it. Bhutan is right to Sikkim in white while Tibet on its top.
It must be noted that in 1962, when this definitive stamp was released Sikkim was still an independent country.