Robert Mugabe, President of Zimbabwe, turns 91 at a time of peak interest in when - or if - he plans to step down and in his successor, now seen as Emmerson Mnangagwa.
Mugabe's 49-year-old wife, Grace Mugabe, was given a top position in the party at the ZANU-PF conference in December 2014, raising expectations that she was being groomed for the succession. The elevation of Mnangagwa to first vice president in the same month is seen as altering the succession picture.
Traditionally, Mugabe's birthday celebrations are lavish and he addresses a rally of his ZANU-PF supporters. In 2015 a special birthday television interview is anticipated. Both will be scanned for more clues about the succession.
Mugabe was re-appointed party leader at the December ZANU-PF congress. He has eye problems and is rumored to suffer from prostate cancer yet is widely believed to be planning to die in office, either before the 2018 election or during a new term as president.
Africa's oldest head of state, he is one of the most controversial leaders in the world. He is feted in some countries as an African revolutionary hero for helping to freeing then-Rhodesia from British colonial rule in the 1970s and shunned in other countries as a tyrant and human rights criminal. His skill at keeping rivals and opposition wrong-footed for some four decades has made him a legend.
Date written/update: 2015-01-19