He had a lengthy career in India, rising to become Governor of Bengal, which effectively made him Governer-General over the three Presidencies (Bengal, Madras and Bombay) where the East India Company was in power. In 1787 he was accused of corruption and impeached. There was a lengthy trial, and he was acquitted in 1795. The prosection brought together Burke (urged on by a mate who had been wounded in a duel by Hastings) with two men who I would have guessed were otherwise political anathema to him, Charles James Fox and Richard Brinsley Sheridan.

Wikipedia seems fairly solid on him and his ambiguous legacy.