East Pakistan was the eastern provincial exclave of Pakistan between 1955 and 1971, covering the territory of the modern country Bangladesh. The province was restructured and renamed from East Bengal, which, in modern times, is split between India and Bangladesh. Its land borders were with India and Burma, with a coastline on the Bay of Bengal. East Pakistanis were popularly known as "Pakistani Bengalis"; to distinguish this region from India's state West Bengal, East Pakistan was known as "Pakistani Bengal". In 1971, East Pakistan became the newly independent state Bangladesh, which means "country of Bengal" or "country of Bengalis" in Bengali language.

Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the fifth-most populous country, with a population of over 241.5 million, having the second-largest Muslim population as of 2023. Islamabad is the nation's capital, while Karachi is its largest city and financial centre. Pakistan is the 33rd-largest country by area and the ninth-largest in Asia. Bounded by the Arabian Sea on the south, the Gulf of Oman on the southwest, and the Sir Creek on the southeast, it shares land borders with India to the east; Afghanistan to the west; Iran to the southwest; and China to the northeast. It shares a maritime border with Oman in the Gulf of Oman, and is separated from Tajikistan in the northwest by Afghanistan's narrow Wakhan Corridor.