Johannesburg - Zimbabwean President Robert Mugabe seemed almost untouchable for much of his nearly four-decade rule.

Shrewd and ruthless, he stayed in power despite advancing age, growing opposition, international sanctions and the dissolving economy of a once-prosperous nation.

Now that it seems to finally be here, the abrupt end of the Mugabe era is launching Zimbabwe into the unknown.

Mugabe, at 93 the world's oldest head of state, is confined to his home after a military takeover. It was the most dramatic development in a factional battle within the ruling Zanu-PF party in which first lady Grace Mugabe had been angling, with Mugabe's help, to take over the presidency in a dynastic succession.

It is a humbling close to Mugabe's career after leading Zimbabwe since independence from white minority rule in 1980.