The Bank of Calcutta (a precursor to the present State Bank of India) was founded on June 2, 1806, mainly to fund General Wellesley's wars against Tipu Sultan and the Marathas. It was renamed Bank of Bengal on January 2, 1809.
The Bank of Calcutta, and two other Presidency banks, namely, the Bank of Bombay and the Bank of Madras were amalgamated and the reorganized banking entity was named the Imperial Bank of India on 27 January 1921. 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.