Once married to a British aid worker, Riek Machar has been a central figure in Sudanese and South Sudanese politics for around three decades.
He is reputed to be a wily operator, switching sides on several occasions during the north-south conflict as he sought to strengthen his own position and that of his Nuer ethnic group in the murky political waters of South Sudan.
Born in 1953, he married Emma McCune in 1991 who died two years later, while pregnant, in a car accident in the Kenyan capital, Nairobi.
She was dubbed by some in the media as the “warlord’s wife”, a reference to Mr Machar’s role as a leading commander in the armed wing of the Sudan People’s Liberation Movement (SPLM), which was then spearheading the war for South Sudan’s independence from the north.
After a peace deal was signed in 2005 to herald the end of the conflict and the sudden death of its leader John Garang, the SPLM appointed Mr Machar as the vice-president of the South Sudan government.
He retained the post after South Sudan became independent in 2011, in a sign of the enormous influenced he wielded in the group until his dismissal in July this year in a government reshuffle.
Coming from South Sudan’s second largest ethnic group, the gap-toothed Mr Machar’s presence in the upper echelons of power was seen as vital to promote ethnic unity with the Dinka majority.
‘Immense patience’Recalling meeting Mr Machar in 2005, BBC Africa’s David Amanor says he had a commanding physique.
“He’s got a steely but also gentle look. He’s well-spoken and well-educated,” he says.
At the time, Mr Machar had swapped his military fatigue for an English suit, playing the role of a mediator between the Ugandan government and the Lord’s Resistance Army (LRA) rebel movement.
He saw the LRA as a major threat, believing that it could destabilise South Sudan, where it had military camps.
Although the peace initiative failed, Mr Machar – now married to South Sudanese politician Angelina Teny – was impressive as a mediator.
“He showed immense patience – the skills of a diplomat,” recalls Mr Amanor, who covered the talks.
But critics say he also showed his ruthless side when he backed government forces in their fight against prominent South Sudan rebel leader George Athor, who was accused of waging a new “proxy war” on behalf of the Khartoum government, which it denied.
In December 2011 – some five months after independence – Mr Machar announced that Mr Athor had been killed near the Sudan-South Sudan border.
‘Prophet of doom’For his SPLM critics, Mr Machar was becoming too powerful – and President Salva Kiir sacked him from the government in July this year without giving a clear reason.
Mr Machar responded by saying that he intended to challenge Mr Kiir for the leadership of the ruling SPLM party so that he could run for president in the 2015 election.
At the time, he called on his supporters not to resort to violence, warning that Mr Kiir would use it as a pretext to declare a state of emergency.
Now, Mr Kiir has accused him of plotting a coup, as government forces clashed with army mutineers in the capital, Juba.
Mr Kiir denounced him as a “prophet of doom”, continuing his actions of the past – an apparent reference to the fact that he had challenged the authority of Mr Garang, the SPLM’s founding leader, in the early 1990s.
Despite high-profile mediation efforts by then-Kenyan President Daniel arap Moi and US congressmen, Mr Machar refused to sign a peace declaration with Mr Garang, who was lionised by SPLM fighters at the time.
This was seen as a major blow to efforts by many African and Western governments to present a united front against the Islamist-led government of Sudan’s President Omar al-Bashir.
By then leading a breakaway rebel group, Mr Machar signed a peace accord with Mr Bashir’s government in 1997.
It gave him his first taste of state power, with his appointment as an assistant to President Bashir, but he quit not long afterwards re-launching a rebellion.
However, Mr Garang’s SPLM remained deeply suspicious of him, accusing him of receiving covert support from the Khartoum government – a charge he denied.
In 2002, he finally buried the hatchet with Mr Garang, rejoining the SPLM.
His career rose after Mr Garang’s sudden death in a 2005 helicopter crash, when Mr Kiir appointed him as vice-president of South Sudan, then a semi-autonomous region.
He held onto the post after South Sudan’s independence, until his fall-out with Mr Kiir in July.
Now, he risks arrest and even death after being accused of plotting a coup – an allegation he is bound to deny as he calculates his next move from his hideout.
It is a far cry from the days when he was a student in the UK, obtaining a PhD in philosophy and strategic planning from the University of Bradford in the mid-1980s.
It was also a time of political revolt in South Sudan, with the SPLM having just been formed to campaign against northern rule.
Mr Machar chose to join the fight – and has never looked back.
Published on 16 December 2013 Last updated at 10:51 ET