Nkosazana Dlamini-Zuma, who is vying to unseat African Union head Jean Ping, is one of South Africa's most powerful women, known for her competent management and stern personality.
A veteran of the fight against apartheid, Dlamini-Zuma, 62, has served in the cabinet of every South African president since Nelson Mandela, who named her health minister after taking office as the country's first black leader in 1994.
A doctor by training, she served as foreign minister for a decade under Mandela's successors Thabo Mbeki and Kgalema Motlanthe, earning praise for her shuttle diplomacy to end the civil war in the Democratic Republic of Congo but raising eyebrows with her unsmiling demeanour and indifference to the media.
Her ex-husband, current President Jacob Zuma, found her indispensable enough to name her home affairs minister - the post she now holds.
Some saw the appointment as a demotion, but she has won plaudits for turning around a ministry that was mired in mismanagement to achieve a clean audit for the first time in 16 years in 2011.
“She takes her work very seriously. She has the rare quality of putting up very good administrators. She insists on professional and talented administrators, which is why she earned a very good reputation,” said Prince Mashele, a political analyst at the Centre for Politics and Research, who worked with Dlamini-Zuma's ministry when she was foreign minister.
“I thought she could do better if she was a little more affable, but that's not her personality. She prefers to project a serious face almost all the time,” he said.
No woman has held the post of chair of the Commission of the African Union. The AU's 54 heads of state and government will hold a secret ballot at a summit in Addis Ababa on January 28-29 to decide whether Ping, who has held the post since 2008, gets a new term.
Born January 27, 1949, in KwaZulu-Natal, Dlamini-Zuma took up student politics in high school and went on to join the anti-apartheid African National Congress (ANC).
In the 1970s, as her activism drew increasing attention from the white regime's security forces, she went into exile, continuing her studies at the universities of Bristol and Liverpool in Britain while helping organise the anti-apartheid movement overseas.
Working as a paediatrician and moving up the ranks of the ANC, she bounced between the party's branches in Britain and southern Africa.
She met Zuma while working at a public hospital in Swaziland in the early 1980s and became his third wife in 1982.
When the ANC's ban was lifted in 1990, Dlamini-Zuma returned to South Africa. She won a spot on the party's national executive committee and after the first democratic elections was tapped by Mandela to transform the country's segregated health system.
She is remembered for introducing legislation that overhauled the highly unequal system and gave poor people access to free basic care.
But Dlamini-Zuma has also been criticised for championing a controversial anti-Aids drug that was later proved ineffective, and for commissioning the Aids education play - Sarafina II - that became the butt of jokes for its huge budget and small audiences.
She and Zuma divorced in 1998.
When her ex-husband fell out with Mbeki and moved to oust him as ANC leader in 2007, she ran against the Zuma ticket in party elections, standing as Mbeki's candidate for deputy ANC president.
Zuma won the vote and went on to become president, but kept his ex-wife in his cabinet - one of the only Mbeki allies to avoid the boot.
“She is an astute politician, a veteran, the experience she acquired as foreign minister puts her in good stead to take over this role” at the AU, said Keith Gottschalk from the University of the Western Cape.
“Her hands on approach makes her a politician of high calibre,” he added. - Sapa-AFP