Bihar and Orissa was a province of British India, which included the present-day Indian states of Bihar, Jharkhand, and Odisha. The territories were conquered by the British in the 18th and 19th centuries, and were governed by the then Indian Civil Service of the Bengal Presidency, the largest administrative subdivision in British India. On 22 March 1912, both Bihar and Orissa divisions were separated from the Bengal Presidency as Bihar and Orissa Province. On 1 April 1936, the province was partitioned into Bihar and the Orissa Provinces.