The Lancaster House Agreement was the independence agreement for Rhodesia, (Zimbabwe). The signing on 21 December 1979 effectively ended white rule in Rhodesia under Ian Smith. The Patriotic Front and the Rhodesian government agreed on a constitution and elections to be hold under British authority. The Thatcher government had started consultations in May 1979. The Lancaster House conference was to begin in September, but the Zimbabwe African National Union (ZANU) under Mugabe felt sure about the outcome. Their posters claimed the victory.