British policy in South Africa was to encourage federation between the British-run Cape Colony and Natal, and the Boer republics, the Transvaal (annexed by Britain in 1877) and the Orange Free State. The governor of Cape Colony, Sir Bartle Frere, believing that the federation could not be accomplished until the native tribes acknowledged British rule, made demands on the Zulu and their king, Cetewayo, which they were certain to reject. As Zulu troops could not marry until they had washed their spears in blood, they were eager for combat. Frere did not send word to the cabinet of what he had done until the ultimatum was about to expire. Disraeli and the cabinet reluctantly backed him, and in early January 1879 resolved to send reinforcements. Before they could arrive, on 22 January, a Zulu "impi", or army, moving with great speed and stealth, ambushed and destroyed a British encampment in South Africa in the Battle of Isandlwana. Over a thousand British and colonial troops were killed. Word of the defeat did not reach London until 12 February. Disraeli wrote the next day, "the terrible disaster has shaken me to the centre". He reprimanded Frere, but left him in charge, attracting fire from all sides. Disraeli sent General Sir Garnet Wolseley as High Commissioner and Commander in Chief, and Cetewayo and the Zulus were crushed at the Battle of Ulundi on 4 July 1879.