Evolution Bank of Bengal June 2, 1806: The Bank of Calcutta established. January 2, 1809: redesigned as Bank of Bengal April 15, 1840: Bank of Bombay established. July 1, 1843: Bank of Madras established. 1861: Paper Currency Act passed January 27, 1921: all 3 banks amalgamated to form Imperial Bank of India July 1, 1955: State Bank of India formed
