The largest bank, and the oldest still in existence, is the State Bank of India. It originated as the Bank of Calcutta in June 1806. In 1809, it was renamed as the Bank of Bengal. This was one of the three banks funded by a presidency government, the other two were the Bank of Bombay and the Bank of Madras. The three banks were merged in 1921 to form the Imperial Bank of India, which upon India's independence, became the State Bank of India in 1955. For many years the presidency banks had acted as quasi-central banks, as did their successors, until the Reserve Bank of India was established in 1935, under the Reserve Bank of India Act, 1934.
