Obasanjo was elected president in 1999
and again four years later [AP]
Olusegun Obasanjo, a retired general elected president of Nigeria in 1999, is due to step down in May and hand power to the winner of this year's elections.

He steps down ater two four-year terms in office as president of Africa's largest oil producer. Nigeria has seen a great deal of growth under his presidency, but most of the country's 140 million inhabitants still live on less than one dollar a day.

Although Obasanjo has portrayed himself as a campaigner against graft and corruption, critics say he has been far more rigorous investigating his opponents than his own administration.

Obasanjo was born in 1937. He joined the army in 1958, at the age of 21, and fought against the Biafran secessionists in the Nigerian civil war.

In 1975, he supported a coup led by Murtala Mohammed, a military general. Although Obasanjo did not directly participate in the coup, he was made Mohammed's deputy in the new administration, which promised a transition to a civilian government.

A year later Mohammed was assasinated in an attempted coup. Obasanjo himself escaped assasination because another general was mistaken for him and killed in his place, leaving  Obasanjo to take over as military ruler of Nigeria.

He pledged to continue with Mohammed's plan to establish a civilian government and in 1979 handed power over to a civilian administration, considered the first time an African military leader has willingly handed over power to a civilian authority.

Nigeria returned to military dictatorship in 1983 and during the 1990s Obasanjo was outspoken against human rights abuses by the government and spent three years in prison. He was released in 1998, publically announcing he was a born-again Christian.

He was elected as president of Nigeria in 1999, in a poll marred by fraud, and re-elected in similar circumstances four years later.

Wole Soyinka, Nigeria's nobel prize-winning poet and playwright, has described him as a "bullish personality, calculating and devious, yet capable of disarming spontaneity ... occasionally  self-deprecating yet intolerant of criticism."

Source: Al Jazeera and agencies