The British government did not approve of the actions of Sir Benjamin d'Urban, and the British Secretary for the Colonies, Lord Glenelg, declared in a letter to the King that "the great evil of the Cape Colony consists in its magnitude" and demanded that the boundary be moved back to the Fish River. He also eventually had d'Urban dismissed from office in 1837. "The Kaffirs," in Lord Glenelg's dispatch of 26 December, "had an ample justification for war; they had to resent, and endeavoured justly, though impotently, to avenge a series of encroachments." This attitude towards the Xhosa was one of the many reasons given by the Voortrekkers for leaving the Cape Colony. The Great Trek, as it is called, lasted from 1836 to 1840. The trekkers (Boers), numbering around 7,000, founded communities with a republican form of government beyond the Orange and Vaal rivers, and in Natal, where they had been preceded, however, by British emigrants. From this time on, Cape Colony ceased to be the only European community in South Africa, though it was the most predominant for many years.