Condolences have poured in from political parties, the legal fraternity and civil society after the news on Saturday that former chief justice Arthur Chaskalson had died.
"Former chief justice Chaskalson passed away earlier today," president Jacob Zuma said in a statement. "We wish the Chaskalson family strength during this difficult time. Our thoughts are with them."
He said Chaskalson left a "special imprint" on the building of a constitutional democracy.
Chaskalson, 81, had been battling leukaemia, according to the South African Broadcasting Corporation.
After being appointed by former president Nelson Mandela, Chaskalson served in the Constitutional Court from 1994 to 2001. He was then appointed as chief justice, a position he retained until his retirement in 2005.
During apartheid, he had represented members of the liberation movement in several major political trials, including the Rivonia Trial.
The African National Congress (ANC) said the country had lost a "sterling" South African who had an "immeasurable impact" on democracy and post-apartheid jurisprudence.
"He was a leading figure in the ANC’s brain trust on constitutional and legal matters," spokesman Jackson Mthembu said in a statement.
Justice Minister Jeff Radebe said South Africa had lost a profound jurist, scholar and a lawyer of "impeccable" intellect.
"He had delivered many trend-setting and guiding speeches, which the government always admired and took counsel from in the course of drafting its policies and legislation," Mr Radebe said.
The South African Council of Churches said Chaskalson had served the legal fraternity with absolute distinction. "He exercised his knowledge and understanding of the constitution with fairness and justice."
The Council for the Advancement of the South African Constitution said the former chief justice had embodied the spirit of "constitutionalism" on which the country’s democracy was based.
"He played a critical role during the constitutional negotiations itself by participating in the drafting process, formulating several of the vital clauses in this founding document (constitution)," it said in a statement.
Democratic Alliance leader Helen Zille said Chaskalson’s contribution to the country’s freedom was "immeasurable", adding: "The realisation of equality and justice for all was a constant thread weaving through all he did. South Africa is immensely enriched by the service he gave to our people and their struggles against oppression."
Former president Thabo Mbeki said Chaskalson was a great human being and a great lawyer who used his intellectual "gifts" to serve his people. He expressed hope that the country’s legal fraternity would build on Chaskalson’s principles.
Chief Justice Mogoeng Mogoeng said he was saddened by the news, adding that Chaskalson’s "contribution and passion for the development of the country’s jurisprudence and its legal institutions cannot be overemphasised and will forever be cherished".
"His passion for the independence of the judiciary and the legal profession was well-known," Justice Mogoeng said, describing Chaskalson as a "fine human being", a "good teacher" and a man of integrity.
"The finest legal mind that he was, he and his team etched their names indelibly in the annals of our history by defending former president Nelson Mandela and his comrades, protecting them against the death penalty during the Rivonia Trial in the early 1960s," said Mogoeng.
The Law Society of South Africa said Chaskalson’s contribution to democracy spanned across his many years as a junior and senior advocate.
"Justice Chaskalson was one of the courageous few who spoke out bravely, and devoted his time and energy to challenging apartheid legislation, at a time when others hesitated to do so," it said in a statement.
The Nelson Mandela Centre of Memory also conveyed its condolences to the Chaskalson family on behalf of the former president, the board of trustees and its staff.
Chaskalson helped establish the Legal Resources Centre, a non-profit organisation that used the law to pursue justice and human rights in the country
In 1990, he received a human rights award in Berne, Switzerland.