According to an aide, Masire, 91, passed away peacefully surrounded by his family in a hospital in the capital Gaborone. "We thank well-wishers and friends from near and far, for their prayers, thoughts and comforting messages of support during this difficult time," Fraser Tlhoiwe, who acted as Masire's senior private secretary until the time of his death, said in a statement.

Masire's family said he had been scheduled to undergo surgery on June 16. He remained in stable condition even though he had been taken into intensive care. Botswana's government posted a statement on Facebook by Masire's family which said he passed away on Thursday night.

Ketumile Masire was born on July 23, 1925 in Kanye, Botswana. He ruled the diamond-rich southern African nation from 1980 to 1998 under the Botswana Democratic Party (BDP).

According to the Huffington Post, he was a leading figure in the independence movement and though he was Botswana's longest serving president, he is credited for introducing the  two-term limits and automatic succession by the deputy in case the president retires.

Following the death of President Seretse Khama in 1980, Masire oversaw a period of unprecedented economic growth. He is regarded as the man who anchored Botswana's stability. The country is one of the few sub-Saharan nations that have enjoyed peaceful transitions since independence in 1966.

Africa's peace-broker

As co-chairperson of an international group tasked with bringing peace to Mozambique, Masire played a crucial role in efforts to end the conflict between Mozambique's government and the main opposition Renamo party.

Clashes erupted across Mozambique after Renamo rejected the results of the 2014 elections accusing the ruling Frelimo party of electoral fraud. Prior to that election, the opposition party had waged a 16-year civil war that ended in 1992.

Masire also led the International Panel of Eminent Personalities in investigating the causes which triggered the Rwandan genocide in 1994. Apart from mediating Mozambique's political crisis, Masire was also instrumental in brokering peace deals in Kenya and Lesotho. He was regarded as one of Africa's most respected elder statesmen.

(cm) AFP/AP