Love him or hate him, President Robert Mugabe who returned home from Singapore today, might be the oldest leader in Africa but he is still not the longest serving. There are four ahead of him. Topping the list is Paul Biya of Cameroon followed by Mohamed Abdelaziz of the Saharawi Arab Democratic Republic, Teodoro Obiang Nguema Mbasogo of Equatorial Guine and Jose Eduardo dos Santos of Angola. Mugabe is fourth if Abdelaziz is not counted. Mugabe was in Singapore for medical check up but there has been speculation that he was not there for an eye check-up but for cancer treatment. A 28- second video of Mugabe allegedly entering a private hospital in Singapore was widely circulated.