Zuma took office in a glitzy ceremony that capped a dramatic political comeback after his ascent to power was nearly derailed by corruption claims and bitter in-fighting within the ruling African National Congress (ANC).
His fierce rivalry with former president Thabo Mbeki, Mandela´s immediate heir, sparked a dramatic power struggle within the party. Zuma ultimately took control in December 2007 and pushed the ANC to sack Mbeki as head of state nine months later, provoking a breakaway from the former liberation movement.
Despite the dissent, he led the party to a thumping victory in general elections on April 22. With Mandela and Mbeki on hand for his swearing-in Saturday, Zuma promised to keep South Africa on a path of reconciliation and to remain open to divergent views.
"He made reconciliation the central theme of his term of office. We will not deviate from that nation building task. Thank you Mandiba for showing us the way," Zuma said, affectionately referring to Mandela by his clan name.
"We must forge a partnership for reconstruction, development and progress. In this partnership there is a place for all South Africans, black and white," he said.
Zuma also made a defense of democracy, political freedoms and free speech as he stood before nearly 30 visiting leaders, including Libyan leader Moamer Kadhafi, Zimbabwe´s President Robert Mugabe and King Mswati III of Swaziland, Africa´s last absolute monarch.
"We must safeguard the independence and integrity of those institutions tasked with the defense of democracy and must act as a check on the abuse of power," he said.
Zuma was accompanied to the stage by the first of his three current wives, Sizakele Khumalo, and after his official speech he went down to the lawns to address the 36,000 cheering supporters who gathered to witness his swearing-in.
The 67-year-old Zuma was elected president by parliament, after the ANC swept to victory in general elections two weeks ago, despite frustrations at poor public services after 15 years as the ruling party.
Zuma has vowed to get straight down to work with a cabinet he will unveil on Sunday to tackle his pledges for rapid improvements to education, unemployment and the alarming crime situation.
He has also promised to work quickly to boost limping public services while bolstering the economy against a looming recession.
A polygamist with 19 children and a murky history with the courts, Zuma embraces his Zulu tradition with a passion that has proved unnerving to some at home and abroad.
He only narrowly dodged a corruption trial when prosecutors dropped the charges charges against him just weeks before the elections.
Related story
South Africa charges Zuma's son with corruption: lawyer
