 In January 1979, Nyerere mobilised the Tanzania People's Defence Force and counterattacked, joined by several groups of Ugandan exiles who had united as the Uganda National Liberation Army (UNLA).Amin's army retreated steadily, and, despite military help from Libya's Muammar Gaddafi, Amin was forced to flee into exile by helicopter on 11 April 1979, when Kampala was captured.He escaped first to Libya, where he stayed until 1980, and ultimately settled in Saudi Arabia, where the Saudi royal family allowed him sanctuary and paid him a generous subsidy in return for staying out of politics.