JOHANNESBURG- South Africa's former deputy president Jacob Zuma is a veteran anti-apartheid fighter whose bid to lead the country largely hinges on the outcome of a sensational corruption trial starting on Monday.

Zuma narrowly escaped political oblivion in May when he was acquitted of the rape of a young AIDS activist, but the arms deal scandal at the heart of next week's trial will be crucial to his future.

The 64-year-old is accused of complicity to accepting a bribe through his financial adviser to protect a local subsidiary of French arms company Thales from a subsequent state investigation into alleged irregularities in the 1999 deal.

Zuma rose from poverty and moved rapidly through the ranks of Africa's oldest liberation movement, the now-governing African National Congress (ANC).

The plain-spoken politician has probably enjoyed more grassroots support than President Thabo Mbeki, dismissed in some circles as an aloof intellectual who is out of touch with the party's rank and file.

But the charismatic number two suffered a blow when Mbeki fired him in June last year and he was charged with corruption, a case that he maintains is part of a political conspiracy intended to crush his presidential ambitions.

His support further waned when he was charged in December with raping a 31-year-old woman, the daughter of an old family friend, at his Johannesburg home.

He apologised after his acquittal but his image undoubtedly took a bashing, especially after he admitted to having unprotected sex with the HIV-positive woman.

Born in 1942 in the town of Inkandla in the Zulu heartland, Jacob Gedleyihlekisa Zuma -- the son of a policeman and a domestic worker -- was brought up in extreme penury by his widowed mother.

He missed out on school but taught himself to read and write.

"I didn't have a father and circumstances did not permit me to go to school ... So I took it upon myself to help myself. I would use other people's books and ask lots of questions," he once said.

"People without formal education are looked down upon and often feel shy... I have done everything the educated have done."

Zuma worked as a cowherd to supplement his mother's meagre income and joined the ANC when he was 17, becoming a member of its armed wing, Umkhonto we Sizwe (Spear of the Nation) three years later.

He was arrested in 1963 and sentenced to 10 years at Robben island prison -- where Nelson Mandela was detained for 18 years -- for conspiring to overthrow the apartheid government.

Following his release, he helped build up the ANC underground in then-Natal province but went into exile in 1975, first in Swaziland, then in Mozambique and finally in Zambia.

In the late 1980s, he was entrusted with running, from Lusaka, the ANC's underground cells and its intelligence department, a position that allowed him to build a network of supporters within the liberation movement.

When the ban against the ANC was lifted in 1990, Zuma was one of the first exiled leaders to return and start operating on home soil.

A skilled negotiator, Zuma is credited with helping to defuse tensions in his home province of KwaZulu-Natal, where fighting between supporters of the ANC and the Zulu-based Inkatha Freedom Party in the run-up to the first democratic elections in 1994 left more than 12,000 dead.

When Mandela stepped down from the presidency in 1999, Mbeki, then his deputy, took over the top post and picked Zuma as his deputy, making him the frontrunner for the presidency in 2009, when Mbeki's second and final term expires.

As deputy president, he successfully led South Africa's peace efforts in Burundi and his diary was filled with public engagements, making him one of the most accessible politicians of the Mbeki administration.

But a lengthy investigation and the conviction last June of his financial adviser Schabir Shaik for corruption sent Zuma's political fortunes into a tailspin.