Zimbabwe's incumbent president Robert Mugabe, 89, was re-elected president for sixth term since 1987, beating his long-time rival Morgan Tsvangirai in polls with big margins. Here are the key dates in Mugabe's life.

1924 Born in Kutama, Zimbabwe (then Southern Rhodesia).

1945 Leaves St. Francis Xavier College, Kutama, qualified as a teacher.

1951 Graduates with a Bachelor of Arts degree - the first of his seven degrees - from the University College of Fort Hare, South Africa.

1952-1959 Teaches school in Southern and Northern Rhodesia (now Zambia) and Ghana.

1960 Joins National Democratic Party (NDP) under Joshua Nkomo, becoming publicity secretary.

1961 Marries Sally Hayfron. Zimbabwe African People's Union (Zapu) formed to replace banned NDP.

1963 Co-founds the Zimbabwe African National Union (Zanu) in Tanzania after having fled Rhodesia.

1964-1974 Arrested after returning to Rhodesia and imprisoned for 10 years. Continues education while in jail and earns university degrees in education, economics, administration and law through distance learning from the University of London.

1974-1979 Released from prison and leads guerrilla movement Zanu from Mozambique.

1977 Gains control of Zanu and its army, elected President of Zanu.

1980-1987 Serves as the first prime minister of independent Zimbabwe, forming the Republic of Zimbabwe after British rule of Rhodesia comes to an end.

1987 Elected by the National Assembly to a four-year term after a new constitution replaces Prime Minister with Executive President. Mugabe and Nkomo signs Unity Accord and forms Zanu-PF (Zimbabwe Africa National Union-Patriotic Front).

1990 Reelected by majority, after a constitutional revision, to a six-year term.

1992 Sally Mugabe dies of kidney failure.

1996 Marries Grace Marufu. Reelected.

2000 War veterans start to seize white-owned farms. Zimbabwe's agricultural output decreases sharply. Zanu-PF wins narrow victory against Movement for Democratic Change (MDC).

2002 The European Union and the United States impose sanctions on Mugabe and some senior Zanu-PF party members after reports of human rights violations. Reelected to anther 6-year presidential term.

2003 Withdraws Zimbabwe from the Commonwealth, a 54-nation organization of Britain and its former colonies.

2008 Results of the 2008 elections show that Mugabe's Zanu-PF party has lost control of parliament. Opposition candidate Morgan Tsvangirai drops out the race, claiming election fraud, violence and arrests targeting his supporters. Mugabe signs a power-sharing deal with political rival Morgan Tsvangirai in order to end months of unrest. Mugabe remains president and Tsvangirai assumes post of prime minister.

2011 Mugabe's Zanu PF party endorses him as its candidate for the new presidential elections.

2013 New constitution approved by an overwhelming majority in a referendum. Future presidents will be limited to two five-year terms. Mugabe beat his long-time rival Tsvangirai in the July 31 elections.