Colebrooke was the son of a wealthy London banker, Sir George Colebrooke, a Member of Parliament, and a man in his time of some political importance. Having proved himself a successful advocate of the old privileges of the East India Company, he was invited to join the Court of Directors, and became in 1769 chairman of the Company. His chairmanship was distinguished in history by the appointment of Warren Hastings to the highest office in India, and there are in existence letters from that illustrious man to Sir George, written in the crisis of his Indian Administration, which show the intimate and confidential relations subsisting between them. But when, in later years, Sir George Colebrooke became involved in pecuniary difficulties, and Indian appointments were successively obtained for his two sons, James Edward and Henry Thomas, it does not appear that Warren Hastings took any active steps to advance them, beyond appointing the elder brother to an office of some importance on his secretariat. Henry, the younger brother, had been educated at home, and at the age of fifteen he had laid a solid foundation in Latin, Greek, French, and particularly in mathematics. As he never seems to have been urged on, he learned what he learned quietly and thoroughly, trying from the first to satisfy himself rather than others. Thus a love of knowledge for its own sake remained firmly engrained in his mind through life, and explains much of what would otherwise remain inexplicable in his literary career. At the age of eighteen he started for India, and arrived at Madras in 1783, having narrowly escaped capture by French cruisers. The times were anxious times for India, and full of interest to an observer of political events. In his very first letter from India Colebrooke thus sketches the political situation:-- “The state of affairs in India seems to bear a far more favorable aspect than for a long time past. The peace with the Mahrattas and the death of Hyder Ally, the intended invasion of Tippoo’s country by the Mahrattas, sufficiently removed all alarm from the country powers; but there are likewise accounts arrived, and which seem to be credited, of the defeat of Tippoo by Colonel Matthews, who commands on the other coast.”