- Before 1912, Bihar was part of the Bengal Presidency. - In 1912, Bihar and Orissa were separated from Bengal and formed a new province under a Proclamation issued under the Government of India Act, 1833. - The Government of India Act, 1935, provided for the creation of new provinces and the redrawing of provincial boundaries. - Under this Act, the provinces of Bihar and Orissa were formally separated from each other and reconstituted as distinct provinces in 1936.