Nelson Mandela said the African National Congress was responsible for making him the person he is today and called for unity in South Africa's governing party.
"I would be nothing without the ANC," Mandela told tens of thousands of people at a rally on Saturday marking his 90th birthday. "The struggle has been my life and the ANC led that struggle."
The crowd broke into thunderous applause and wild cheers as Mandela made his way on to the stage at a local sports stadium.
Wearing a gold patterned shirt, Mandela looked thrilled, smiled and waved to the crowd.
He urged people to not focus their celebrations on him but rather the party that helped bring about the end of white racist rule in South Africa.
"Do not celebrate an individual," he said. "Celebrate the achievements and reaffirm the values of a great organization."
Mandela was flanked by President Thabo Mbeki and ANC president Jacob Zuma. The two fought bitterly over the party leadership last year. The battle seriously damaged the reputation of the party as it heads for general elections next year.
Mandela made an impassioned plea for unity and strong leadership.
"Let no individual, section, faction or group ever regard itself as greater than the organization," he said.
"Our nation comes from a history of deep division and strife; let us never, through our deeds or words, take our people back down that road."
Mandela was imprisoned for nearly three decades for his fight against apartheid.