The Bank of Calcutta (a precursor to the present State Bank of India) was founded on 2 June 1806, mainly to fund General Arthur Wellesley's wars against Tipu Sultan and the Marathas. It was the tenth oldest bank in India and was renamed Bank of Bengal on 2 January 1809.

The bank opened branches at Rangoon (1861), Patna (1862), Mirzapur (1862), and Benares (1862). When it became known that the bank intended to open a branch at Dacca, negotiations began that resulted in Bank of Bengal in 1862 amalgamating The Dacca Bank (1846).^[1] A branch at Cawnpore followed.

Among the bank's renowned customers were scholar and politician Dadabhai Naoroji, scientist Jagadish Chandra Bose, India's first President Rajendra Prasad, Nobel laureate Rabindranath Tagore, and educationalist Ishwar Chandra Vidyasagar.^[2]

The bank was risk averse and would not lend for more than three months, leading to local businessmen, both British and Indian, launching private banks, many of which failed. The most storied bank failure was The Union Bank (1828) founded by Dwarakanath Tagore in partnership with British companies.^[3]

The Bank of Calcutta, and the two other Presidency banks — the Bank of Bombay and the Bank of Madras — amalgamated on 27 January 1921. The reorganized banking entity assumed the name Imperial Bank of India.^[4] 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 renamed on 30 April 1955 as the State Bank of India.

• Banking in India
• History of banking
• List of banks that have merged to form the State Bank of India