Nelson Mandela has issued a statement, paying tribute to former South African President PW Botha, who died at the age of 90 on Tuesday.
Mr Mandela said Mr Botha helped to usher in the end of apartheid
He described Mr Botha as a "symbol of apartheid", but recalled that he took steps towards an "eventual peacefully negotiated settlement" in the country.
Mr Botha led white minority rule between 1978 and 1989 at the height of the anti-apartheid struggle.
Flags are to fly at half-mast until a private funeral expected next week.
Mr Botha's widow, Barbara, told the South African media her husband would not have wanted a state funeral as was his right under the constitution - and a funeral near his home is being planned for next Wednesday.
"He wasn't a man who looked for honour and glory," she said.
BBC southern Africa correspondent Peter Biles says Mr Botha will be remembered as the face of defiance.
He was the man who refused to release Nelson Mandela from prison and presided over a state of emergency in a failed attempt to quell opposition to the apartheid system.
Yet the governing African National Congress, which was outlawed under Mr Botha, was among the first to offer condolences on Tuesday.
1916: Born 12 January
1948: Elected MP
1966: Defence minister
1978: PM of South Africa
1984: Elected president
1989: Resigns the presidency
2006: Dies, aged 90
"The African National Congress extends its sympathies and condolences to the family, friends and colleagues of former President PW Botha, who passed away. The ANC wishes his family strength and comfort at this difficult time," it said in a brief statement.
Former state president FW De Klerk, who succeeded Mr Botha, also made a statement on Wednesday.
"PW Botha was a strong leader and an effective organiser. I would like to honour Botha for the enormous contribution that he made to preparing the way to the new South Africa."
Mr de Klerk went on to lead South Africa to multi-racial polls.
Mr Botha - known by Afrikaners as the Great Crocodile - died at his home in the Western Cape after 17 years in retirement.
Mr Botha was regarded as a relic and someone stuck in a bit of a time warp, our correspondent says.
In the 1990s, Mr Botha was summoned to appear before the Truth and Reconciliation Commission, a panel set up by then President Mandela's government to probe abuses.
The panel concluded in 1998 that Mr Botha was guilty of gross human rights violations.
Thousands were detained without trial during his presidency, while others were tortured and killed. However, he refused to apologise for apartheid.
Although some cosmetic reforms were introduced in 1983, allowing the Asian and mixed-race communities into parliament, Mr Botha made no headway in terms of advancing political freedom.
He imposed a state emergency in 1986 after South Africa's black majority did not accept his reforms.
Mr Botha failed to satisfy those on either side of the country's racial divide - or international opinion - and eventually resigned after a power struggle within his cabinet.
He led a quiet life with his second wife, Barbara, in the seaside village of Wilderness, about 350km (220 miles) east of Cape Town, for almost two decades.
In an interview to mark his 90th birthday, he suggested that he had no regrets about the way he ran the country.
Mr Mandela's statement said: "While to many Mr Botha will remain a symbol of apartheid, we also remember him for the steps he took to pave the way towards the eventual peacefully negotiated settlement in our country."