In 1757, the Nawab of Bengal captured the Company's settlement at Calcutta. The Company had refused to stop strengthening its walls against a possible attack by the French. The Company recaptured the settlement at the Battle of Plassey, and took control of the whole of Bengal, India's richest province.
From this time on, the East India Company became more of a ruling power than a trading company in India. While the Company grew richer on the profits of its trade, land taxes shot up, and millions of Indians died in terrible famines. Over the following two decades, millions more would be disposessed of their land, and have their local industries crippled by the actions of the Company.
The British government became concerned about the Company's ability to govern its territories and in 1783 it decided to make Calcutta the centre of government under a new Governor-General.
The first person appointed to this role was Warren Hastings. Power gradually slipped away from the Company into the hands of the British government.
By 1813 the Company's trade was limited to China, but these powers were abolished in 1833. The Company lingered on until 1857 when there was a rebellion in Bengal by the "Sepoys", who were Indian troops employed by the Company. This is believed to be India's first war of Independence. The Company was abolished in 1858.