Kgalema Motlanthe has been sworn in as South Africa's caretaker president until next year's elections.
Kgalema Motlanthe cut his political teeth as a trade unionist
He was not even an MP until May this year but has a long history as an official in the ruling African National Congress and a trade unionist.
He is seen as a close ally of ANC leader Jacob Zuma, who is expected to become South African president after elections due next year.
Correspondents say Mr Motlanthe's low public profile and lack of a personal support base mean he is regarded as a safe interim president - there is no way he could possibly hold on to the presidency once Mr Zuma decides his time has come.
Asked after his election last year as the ANC's deputy president whether he was interested in the top job, he replied he would prefer to oversee the country's national football team, Bafana Bafana.
At school, Mr Motlanthe was influenced by the ideologies of the Black Consciousness Movement and the late anti-apartheid campaigner Steve Biko.
He cut his political teeth in the National Union of Mineworkers, working there from 1987 when he was released after serving 10 years on Robben Island - where Nelson Mandela was also imprisoned.
He had been sent to jail for his activism a year after the 1976 Soweto uprising, when black students fought against the policy forcing them to learn in Afrikaans.
His political rise has been slow but sure.
In 1997, he became ANC secretary general and 10 years later he was elected as the ruling party's deputy president.
1967: Detained for 11 months
1977: Sentenced to 10 years on Robben Island
1987: Joined National Union of Mineworkers, rising to become its secretary general
1997: Elected ANC secretary general
2007: Elected ANC's deputy president
2008: Becomes an MP and minister without portfolio
Affectionately known as "Mkhulu" (grandfather in Zulu), he is well respected by both the core supporters of bitter rivals - outgoing president Thabo Mbeki and Mr Zuma.
According to South Africa's Business Day paper, he is regarded by many "as the glue that holds the tripartite alliance [ANC, South African Communist Party and trade union federation Cosatu] together".
Usually smartly dressed in a blazer and tailored trousers, the 59-year-old has publicly defended the ANC's decision to back Mr Zuma in his battle against corruption charges.
Earlier this month, a judge suggested what Mr Zuma's supporters have always claimed - that the government may have interfered in the case, a statement that led to Mr Mbeki's resignation.
But Mr Motlanthe has also proved that he can be his own man.
During the bitter dispute over the corruption case, ANC Youth League leader Julius Malema said he was prepared to kill for Mr Zuma.
Zuma supporters said they would organise huge protests outside the court, which some saw as an attempt to intimidate the judge hearing the case.
Mr Motlanthe responded by urging the Youth League to respect the judiciary, earning the respect of many in the country.
Little is known about his personal life. On his government profile his marital status is listed as "unavailable". However, he is known to be married with three children and is a jazz enthusiast.
Author Richard Calland says he is the son of a miner.
Mr Motlanthe acknowledged to South African journalist Karima Brown that he has always been careful to guard his privacy.
"I took a decision a long time ago that when I became involved in politics I would try shield my family from the glare of public life," he said.
But according to Mr Calland, Mr Motlanthe is well-known in the party.
In his book Anatomy of South Africa: Who Holds the Power?, he remembers Mr Motlanthe's election as ANC secretary-general.
"When the result was announced, he was carried from the back by a group of supporters. It took another 15 minutes for him to reach the stage, struggle songs filling the air."
When he was appointed as minister without portfolio in Mr Mbeki's cabinet earlier this year, it was seen as an attempt to smooth the transition to a post-Mbeki era.
The BBC's Mohammed Allie in Cape Town, where parliament sits, says Mr Motlanthe accepted the post reluctantly and it took weeks of persuasion by the ANC leadership before he relented.
Now he is to become South Africa's president, albeit for just a few months.