LONDON — In August, he stood shoulder to shoulder in Beijing with President Xi Jinping of China. Then, in September, he addressed the United Nations to condemn “the evil machinations of Western countries” seeking his overthrow. And just this month, he eulogized a neighbor and political ally at the state funeral of President Michael Chilufya Sata of Zambia.

Hemmed in by travel restrictions in the West, except for journeys to international gatherings, and reviled by many governments for his record on human rights, President Robert G. Mugabe of Zimbabwe, Africa’s oldest leader at 90, still struts a somewhat diminished stage as head of state, one of a shrinking band of the continent’s longstanding rulers and political survivors.

But back home, he is presiding over — and possibly choreographing — an increasingly fierce internal scramble for the rewards of high office.

The land is seething with intimations of conspiracy and counterconspiracy. In recent days, a state-run newspaper reported that his vice president, Joice Mujuru, 59, was linked to a plot to assassinate him, a charge she vigorously denied. Then his wife, Grace Mugabe, 49, said the vice president planned to kill her, too, intensifying the battle for control of the country after Mr. Mugabe dies.