30 September 1966
Previously known as Bechuanaland, Botswana gained independence from Britain on 30 September 1966 under the leadership of Seretse Khama. Khama was elected president by the National Assembly in 1966 and then reelected for two additional terms, until he passed away in 1980. Botswana is rich of natural resources like diamond and today the country has achieved one of the highest per capita income rates in Africa.
References

Democracy Web, ‘Accountability and Transparency: Country Studies – Botswana’, [online], available at www.democracyweb.org (Accessed: 03 September 2013)|

Boddy-Evans, A. ‘This Day in African History: 30 September’, [online], available at https://africanhistory.about.com (Accessed: 03 September 2013)