16 January 2006
Ellen Johnson-Sirleaf became the first elected woman as Head of State in Africa. Johnson-Sirleaf’s historic inauguration as President of Liberia was on 16 January, 2006. She became the 24th President of Liberia. Her historic achievement was the culmination of decades of fighting for freedom, justice and equality in Liberia. In 2011 President Johnson-Sirleaf shared the prestigious Nobel Prize for Peace with two other women, fellow Liberian Leymah Gbowee and Tawakkul Karman of Yemen.  History repeated itself when she was re-elected in November 2011, and was inauguratedon 16 January 2012 to a second and final term of office. This event coincided with her six-year anniversary as Liberian President.  
References

Government of the Republic of Liberia, ‘Biographical Brief of Ellen Johnson Sirleaf’, from Executive Mansion, [online], Available at www.emansion.gov.lr [Accessed: 16 November 2012]|Biography, ‘Ellen Johnson Sirleaf biography’, from bio.TrueStory, [online], Available at www.biography.com [Accessed: 16 November 2012]