East Bengal (Bengali: পূর্ব বেঙ্গল) is the eastern part of Bengal. East and West Bengal were once part of British India. After the British left, the east and west parts of Bengal were split between Pakistan and the Republic of India's West Bengal province, with an area of 55,126 mi2 or (142,776 km2). East Bengal also used to be called East Pakistan until it became independent from Pakistan. Today it is called Bangladesh.
Before 1905, the first time it was called "East Bengal" was during British rule of India. British rule of a large area of Indian territory began with Robert Clive's win over the Nawab of Bengal, Siraj ud-Daulah, at the Battle of Plassey in 1757. The win gave the British East India Company dominion over Bengal, which became the headquarters of British administration in the sub-continent. After the Indian Rebellion of 1857, (known as the "Mutiny"), the British government took direct control away from the East India Co., and got its imperial capital at Calcutta, the city founded by the Company. By 1900, the British place of Bengal was a big territory, all the way from the Burmese border to deep into the "Ganges valley."