Foday Sankoh, the leader of a 10-year terror campaign in Sierra Leone, has died while waiting to be tried for war crimes.
By March Sankoh's deteriorating health was clearly visible
The spokesperson for the United Nations-backed war crimes tribunal in Sierra Leone told BBC News Online that he had died at 2240 GMT on Tuesday.
Sources say he died from complications resulting from a stroke he suffered last year.
Sankoh founded the Revolutionary United Front (RUF) which became notorious for mass rape and hacking off the hands, feet, ears and noses of thousands of civilians during a 10-year civil war, which ended last year.
He was detained in 2000 and is believed to have died in Choithrams hospital in western Freetown where he has been since April after suffering a partial stroke.
According to a statement from the Special Court for Sierra Leone's chief prosecutor, David Crane, Sankoh's death from natural causes granted him "a peaceful end that he denied to so many others".
The court last week rejected a request to drop murder charges against him on health grounds.
In June court registrar Robin Vincent said the tribunal had hoped to send him abroad for medical treatment.
However, the court had then reported that it could not find a country that was willing to accept the rebel leader even for short-term treatment.
At one court hearing last year, he said he was "surprised that I am being tried because I am the leader of the world".
Earlier this month doctors treating Sankoh said he was in a "catatonic state" - incapable of walking, talking or even of feeding himself and he could not recognise his immediate surroundings.
Sankoh, like President Charles Taylor of neighbouring Liberia, trained in the guerrilla camps of Libyan leader Muammar Gaddafi.
He was captured after his fighters shot more than a dozen protesters outside his Freetown home in 2000.
The war in Sierra Leone was formally declared over in 2002 following military intervention by the UK and the UN.