11 April 1979
Idi Dada Amin ruled Uganda from 1971 until 1979 after he unconstitutionally seized power from president Obote Milton. However, in 1979 he suffers the same fate when he is overthrown by a military coup launched by rebels and exiles backed by Tanzanian forces. In October 1978 Amin launched an attack on western Tanzania. This resulted in a counter-attack by the Tanzanian army, which managed to work its way to the Ugandan capital of Kampala in early 1979. In April 1979 Amin flees to Libya and leaves Tanzania in sole charge of the country.
References

Bute, E.L. & Harmer, H.J.P. (1997). The Black Handbook, London: Cassell.|History, This Day in History 11/04/1979, from History.com, [online], Available at www.history.com [Accessed: 10 April 2014]