Professor Denis Goldberg, a close friend of Nelson Mandela, was in Glasgow yesterday to mark the 20th anniversary of Mr Mandela's visit to the city.
Mr Mandela had been given the Freedom of the City in 1981 and the council renamed St George's Place to Nelson Mandela Place in 1986, much to the annoyance of the South African Consulate which was based there at the time.
Professor Goldberg spent 22 years in jail for his activism with the ANC's military wing, Umkhonto we Sizwe (MK), for whom he was a weapons manufacturer.
He was at the Riverside Museum yesterday where he viewed the Glasgow-built South African Railways Locomotive.
Professor Goldberg, 80, said: "Glasgow awarding the Freedom of the City to Nelson Mandela and renaming a street after him, along with the Freedom March from Glasgow to London, were all very important to us because it said to the oppressors, 'you are intolerant and we won't accept it'.
"And what it said to the oppressed was 'we support you'. One needs to know that there are people around the world who support your struggle. I always love coming to Glasgow."
On October 9, 1993, Mr Mandela arrived in Glasgow to collect the Freedom of the City.
That day, as the apartheid regime was nearing its end, Mr Mandela said: "While we were physically denied our freedom in the country or our birth, a city 6000 miles away, and as renowned as Glasgow, refused to accept the legitimacy of the apartheid system and declared us to be free."
Professor Goldberg was the only white man to be jailed as part of the Rivonia trials 50 years ago.
Handed four life terms, he was released after serving 22 years in prison.
Brian Filling, a leading anti-apartheid campaigner and Honorary Consul for South Africa in Scotland, helped to organise the 1993 visit.
He said: "It was a great day in Glasgow's history and people who were there that day still talk fondly of their vivid memories."