Michael Sata is the most recent African president to have died while in office. He died at the age of 77 of an undisclosed illness in the United Kingdom on October 28th, 2014. After his election in 2011, rumors about his failing health spread across Zambia. His continuous absence at major state functions raised concerns about his well-being, even though his spokesmen said he was in good health.

Meles Zenawi died in August of 2012 in Belgium at the age of 57 of an undisclosed infection. He led Ethiopia for a total of 21 years, as president from 1991 to 1995 and as prime minister from 1995 to 2012. He is known for introducing multi-party democracy, but also for violently suppressing the legitimate protests of the Oromia people of northern Ethiopia.

Also in 2012, John Atta Mills, the president of Ghana, died in his home country of stroke and throat cancer at the age of 68. He won the presidential election in 2008 and was in office for only three years. As president, he instituted a number of far-reaching economic and social reforms that earned him both local and international commendations.

Another president to die in 2012 is Bingu wa Mutharika, the president of Malawi. He suffered a heart attack in April and died two days later at the age of 78. His tenure was eight years long and he achieved broad success with his food and agricultural policies. His reputation was damaged by widespread public protests over his purchase of a $14 million (13.2 million euros) presidential jet.

The fourth leader to die in 2012 was Malam Bacai Sanha, the president of Guinea-Bissau. He suffered from diabetes and died in Paris after four years as president at the age of 64. Throughout his time in office, he suffered from several health complications and was continually in and out of the hospital.

A victim of assassination, Moammar Gadhafi was the self-professed Libyan leader and guide to the revolution. He was killed at the age of 69 by rebel forces in unclear circumstances in Libya, after being its leader for 42 years. He seized power from the Libyan monarchy following a bloodless military coup in 1969 but his leadership came to an end in the aftermath of the "Arab spring" revolution.

Umaru Musa Yar’Adua, the president of Nigeria, died at the age of 58 in 2011 from pericarditis in Nigeria. He had been in office for only three years. His election campaign was punctuated by the absence of the candidate on the campaign trail complete with reports of health-related complications. After his election in April 2007, Yar’Adua’s health deteriorated quickly.

Joao Bernardo Vieira, the president of Guinea-Bissau, was assassinated in his own country in March 2009 at the age of 69. He was the head of state for a combined 31 years. In 1978, he became prime minister and seized power in 1980 and ruled for 19 years. He morphed into a civilian president and led for another four-year period. In 2005, Vieira won another round of presidential elections.

Advanced intestinal cancer killed Omar Bongo in June 2009 in Barcelona, Spain, after being in office for 42 consecutive years. He died aged 72 and was one of the longest-serving rulers in history and also one of the most corrupt. Bongo collected immense private wealth while his country lived in poverty despite Gabon’s huge revenue earnings from its extensive oil deposits.

After 24 years, Lansana Conte died of undisclosed illness at the age of 74. He battled complications from diabetes and heart-related conditions. From April 1984 until his death in December 2008, he served as the second president of the country. Despite his health issues for which he constantly sought medical treatment abroad, he won three elections.