15 October 1989
On 15 October 1989, five of the eight African National Congress (ANC) long term political prisoners were released from Robben Island. Among those leaders who were set free were Walter Sisulu, Ahmed Kathrada, Raymond Mhlaba, Endrew Mlangeni and Elias Motsoaledi. Three of the eight prisoners who were released before and after 1989 were, Dennis Goldberg (1985), Govan Mbeki (5 November 1987) and Nelson Mandela (11 February 1990). They were arrested on 11 July 1963 when security police raided Liliesleaf Farm which was the ANC’s underground headquarters after movement was banned in April 1960 under the Unlawful Organisation Act. During the raid scores of ANC leadership members and uMkhonto weSizwe commanders were apprehended and a large number of ANC documents were confiscated. The trial became known as the Rivonia Trial. On 11 June 1964, almost a year into the trial, Judge Quartus de Wet delivered his verdict, where all the accused were found guilty with the exception of Rusty Bernstein as the evidence against him was not sufficient.
References

Gerhart, G.M (2007). ‘The Rivonia Trial 1963-1964’ from Aluka [online] Available at www.aluka.org [Accessed 15 September 2011]|Liliesleaf Trust (no date). ‘The Raid’ from Liliesleaf Farm [online] Available at www.liliesleaf.co.za [Accessed 15 September 2011]