Imperial Bank of India
The Imperial Bank of India came into existence on 27 January 1921 by J.M. Keynes. when the three Presidency Banks of colonial India, were reorganized and amalgamated to form a single banking entity. The three Presidency banks were the Bank of Bengal, established on 2 June 1806, the Bank of Bombay (incorporated on 15 April 1840) and the Bank of Madras (incorporated on 1843
Imperial Bank of India performed all the normal functions which a commercial bank was expected to perform. In the absence of any central banking institution in India until 1935, the Imperial Bank of India also performed a number of functions which are normally carried out by a central bank.
- In 1924, at Apollo Street, currently called Mumbai Samachar Marg, Mumbai, a magnificent stone structure  with fretted windows, was constructed to house a branch of the Imperial Bank of India.
- In 1933, Sir Badridas Goenka, an important public figure and business tycoon of his time, and a prominent member of Marwari community of Calcutta, became the first Indian to be appointed as the Chairman of the Imperial Bank of India.
The Reserve Bank of India, which is the central banking organization of India, in the year 1955, acquired a controlling interest in the Imperial Bank of India, and the Imperial Bank of India was christened on 30 April 1955 as the State Bank of India, and this transformation from the Imperial Bank of India to the State Bank of India was given legal recognition in terms off an Act of the Parliament of India, which came into force from 1 July 1955. The day on which the Imperial Bank of India (IBI) became the State Bank of India, IBI had 480 branches, sub-offices, and three local head offices; and had under its control and command slightly more than a quarter of the resources of the Indian banking industry. The branch network of State Bank of India has since grown to 9093 branches as on 31 March 2004. In 2007 Reserve Bank of India transferred its stake in State Bank of India to Government of India.
- The Evolution of the State Bank of India Volume III (The Era of the Imperial Bank of India, 1921-1955) Edited by State Bank of India (ISBN 0-7619-9696-6)
- THE EVOLUTION OF THE STATE BANK OF INDIA, Volume 1 — The Roots 1806-1876 by Amiya Kumar Bagchi