Jacob Zuma, South Africa's ruling party chief who on Friday won a protracted court battle against corruption charges, is a populist who has had constant brushes with controversy as he closes in on the country's presidency.

In line with his exuberant reputation, supporters hugged Zuma (66), dressed in his striped black suit after a court ruled that he had no charges to answer.

Zuma's style has many detractors, but he also has intensely committed supporters, including the head of the African National Congress (ANC) youth league, Julius Malema, who said in June he was "prepared to take up arms and kill for Zuma."

The general secretary of the Congress of South African Trade Unions (Cosatu), Zwelinzima Vavi also vowed to "kill and die" for Zuma who ousted President Thabo Mbeki as chief of the ANC.

An ethnic Zulu, Zuma has always been a sharp dresser who has taken an avowedly populist approach to politics.

Idolised by his mostly leftist backers as a champion of the poor, the ever-smiling Zuma has unnerved the markets and the ANC old guard who recall the disciplined nature of the movement when it was at the vanguard of the fight against apartheid.

Under apartheid rule, Zuma spent some 10 years in prison alongside Nelson Mandela on the notorious Robben Island penal colony.

Like Mandela, he has an instinctive rapport with people characterised by his tendency to break into dance often accompanied by supporters singing his signature tune "Umshini Wami" (Zulu for "Bring Me My Machine-Gun").

"In Zuma we see ourselves, we see humility, down to earth. We see somebody we can speak to, who has a genuine love for people," said Vavi.

Even Nobel laureate Archbishop Desmond Tutu concedes Zuma is a "likeable" person, but adds that he has a track record that would "shame" the country were he to become president.

Zuma was fired by President Thabo Mbeki as deputy head of state in June 2005 after his financial adviser was jailed for canvassing bribes for him.

In 2006, he was acquitted of rape but ridiculed for testifying in court that after having consensual sex with his HIV-positive accuser, he believed taking a shower after sex was sufficient protection against infection. He was head of the National Aids Council at the time.

Born in rural Inkandla in eastern KwaZulu-Natal Province, Zuma, the son of a domestic worker, had no formal schooling.

He joined the ANC in 1958 and was convicted of trying to overthrow the apartheid government five years later and was sent to Robben Island for a decade.

He went into exile for 12 years in Mozambique, Swaziland and Zambia — where he was the ANC's chief of intelligence.

Zuma returned to South Africa after a ban on the ANC was lifted in 1990, and was a key figure in talks with the National Party regime that led to a negotiated national unity government.

Married to at least four wives, since ousting Mbeki as ANC chief, Zuma has started visiting major countries within and outside Africa, in what observers see as an effort to "market" himself and the ANC.

AFP