27 February 1980
After a war of independence fought between members of various liberation organisations and the illegal Rhodesian government, with the liberation organisation supported by groups such as the African National Congress (ANC) and the Pan Africanist Congress (PAC) and the Rhodesians by the Apartheid South African government an agreement was struck. The Lancaster agreement that Britain helped draft led to peace in the country and its the first multi-racial elections. These elections gave Zimbabwe it's first Black president, Robert Mugabe.
References

Bulawayo (1872), "The History of Zimbabwe",From: Bulawayo,[online] Available at: www.bulawayo1872.com[Accessed on 21 February 2013]