At 90 years of age, Robert Mugabe is Africa’s oldest head of state. Mugabe was elected prime minister in 1980 and seven years later became president. Initially he was regarded as a freedom fighter but lately his regime has led to a food and financial crisis. Last year, Mugabe changed the constitution which means he could now govern until he is 97.

No African head of state has ruled longer. The 72-year-old leader seized power in oil-rich Equatorial Guinea in 1979. Obiang has changed the country’s constitution at least three times: in 1982, 1991 and most recently in 2011 by a referendum. Although he left the term limit to two mandates, each of seven years, he had the age limit of 75 years removed.

The Angolan president has ruled for more than 35 years. He was elected for the first time after the death of Angola's first president Agostinho Neto. A new constitution stipulates that the chairman of the party with the most votes in parliament becomes the president automatically. Dos Santos' MPLA party is the strongest in Angola, meaning the 72-year-old could remain in power for years to come.

Paul Biya has ruled the western central African country since 1982. Cameroon's former constitution would have barred him from standing for re-election. But in 2008, he changed the laws and removed all restrictions on term limits, despite massive protests from the population. His re-election in 2011 did not come as a surprise. The opposition and critics accuse him of election fraud.

Museveni came to power in 1986, bringing an end to Idi Amin's dictatorship in Uganda. But after ruling the east African country for 28 years, thanks to several constitutional amendments, Museveni has himself come to be known as a dictator. In 2005, he finally scrapped term limits even though he was the one who once declared: "No African head of state should be in power for more than 10 years."

He came to power without a constitutional amendment simply because there is no constitution in Swaziland. Mswati III is the last absolute ruler in Africa. At the age of 18, he ascended the throne in 1986 after the death of his father, King Sobhuza II. Since then he has ruled the country by decree and rejects any form of democracy. Swaziland remains one of the poorest countries in the world.

Born in 1952, Idriss Deby Itno began his career as a rebel fighter. In 1990 he overthrew the government of his former comrade Hissene Habre and became president one year later. In 2004, he amended the constitution to allow him to remain in office. Rebels tried to overthrow his government in 2006 and 2008 but in vain. In 2011 he was re-elected for a fourth term.

Kabila is, in comparison to his counterparts, still a young head of state and has not held office for a long period of time. The 43 year-old has ruled the conflict-ridden DRC since 2001. After his father, President Laurent Kabila, was assassinated, he was installed as his successor. Kabila was elected in 2006 for the first time but has called for a constitutional amendment in order to run again.