East Pakistan was the eastern provincial wing of Pakistan between 1947 and 1971, covering the territory of the modern country 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 the India's state West Bengal (which is also known as "Indian Bengal"), East Pakistan was known as "Pakistani Bengal".
Hopes this helps
