When the Brits annexed the South African Cape Colony in 1806, they found an established settlement with about 25,000 slaves, 20,000 white colonists, 15,000 Khoikhoi and coloured. Power resided solely with a white elite in Cape Town. Of the whites about 80 percent were Boers, orthodox and godly, in a pastoral world enrooted people. Differentiation on the basis of race was deeply entrenched and strictly observed. With the rising number of British immigrants, the Boers lost their dominant position, however. A pattern soon emerged whereby English speakers became highly urbanized, and dominated politics, trade, finance, mining and manufacturing, while the largely uneducated Boers were relegated to their farms. Hence to back out of the British sphere of power, many Boers retreated to the hinterlands. In 1835 thousands of Boers decided to trek off into the interior in search of greater independence.