Johannesburg: Walter Sisulu, a charismatic, quiet leader who brought Nelson Mandela into the African National Congress (ANC) and helped lead the fight against apartheid for five decades has died. He was 90.

Sisulu, who died on May 5, had been suffering from a long illness, according to the ANC.

"His absence has carved a void. A part of me is gone," Mandela said in a statement sent to the South African Press Association.

Sisulu and Mandela stood together throughout the fight against the racist apartheid regime. They went on trial together, went to jail together and worked together to transform the organisation from a banned liberation movement to the nation's governing party.

"Together we shared ideas, forged common commitments," Mandela said. "We walked side by side through the valley of death, nursing each other's bruises, holding each other up when our steps faltered. Together we savoured the taste of freedom."

While Mandela became the public face of resistance – and eventually the nation's first black president – Sisulu, perhaps his closest confidant, remained the clear-thinking strategist in the background.

"(Sisulu) stands head and shoulders above all of us in South Africa," Mandela told a group of South African children recently. "You will ask what is the reason for his elevated status among us. Very simple, it is humility. It is simplicity. Because he pushed all of us forward and remained quietly in the background."

Sisulu's entire family threw itself into the anti-apartheid struggle and suffered deeply for it. His wife Albertina's movements and speech were restricted from 1964-81, and she spent 10 years under house arrest. Four of their five children have spent time in exile or in prison.

"This government doesn't feel comfortable unless it has a Sisulu in jail," his son Zwelakhe once joked.

In a sign of the huge change in South Africa since the fall of the apartheid regime, Zwelakhe became head of the state broadcasting corporation and Sisulu's daughter Lindiwe became the nation's Intelligence Minister.

In a 1994 interview, Sisulu welcomed the end of apartheid, but said much more needed to be done.

"I can never be satisfied until we have consolidated the unity of the people of South Africa, until the economic position has been radically improved and…we are able to meet the aspirations of our people," the white-haired, bespectacled Sisulu said.

More than any other black leader, Walter Max Ulyate Sisulu's life mirrored the history of the ANC. They were born the same year, 1912, and the young Sisulu developed a deep-rooted militancy because of his mixed-race ancestry and hatred of his family's deference to whites.

The son of a poor family in the Xhosa homeland of Transkei, Sisulu left home at 15 to seek work in Johannesburg. He worked as a baker's assistant, domestic servant, dairy worker, factory labourer and gold miner – and often found himself leading labourers in disputes with bosses.

Agencies