Finding the Bengal Presidency too large for one governor to administer, in 1905 the English decided to redraw its boundaries and divided it into two parts.
The provinces of Bengal and Assam were reconstituted so as to form the two provinces of manageable size. Western Bengal, with a population of 54 million (42 million Hindus and 9 million Muslims); and Eastern Bengal and Assam with a population of 31 million (12 million Hindus and 18 million Muslims). The territory to be transferred from Bengal to the new province consisted of the districts of Chittagong and Dhaka Divisions, Rajshahi Division excluding Darjeeling, and the District of Malda.
Curzon, the Viceroy of India, sent the proposal to London in February 1905. The Secretary of State for India St. John Brodrich sanctioned it in June, and the proclamation of the formation of the new province was issued in September. The province of Bengal and Assam came into being on October 16 1905.
Incidentally, the partition went in favor of the Muslims. Before the partition, Western Bengal, being the first area to come under western influence, was developed and industrialized. It was a striking contrast to the eastern part where the Muslim peasantry was crushed under the Hindu landlords, the river system was infested with pirates, and very few funds were allocated for education. It was dreaded as a place of banishment. The partition helped boost Bengali literature and language; efforts were also made towards the social, economic and educational uplift of the Muslims.
The Muslims outnumbered the Hindus in Eastern Bengal and this alleviated the Bengali Muslims politically and