On 5 August 1962, police captured Mandela along with Cecil Williams near Howick. Jailed in Johannesburg's Marshall Square prison, he was charged with inciting workers' strikes and leaving the country without permission.
Representing himself with Slovo as legal advisor, Mandela intended to use the trial to showcase "the ANC's moral opposition to racism" while supporters demonstrated outside the court. Moved to Pretoria, where Winnie could visit him, in his cell he began correspondence studies for a Bachelor of Laws (LLB) degree from the University of London.
His hearing began on 15 October, but he disrupted proceedings by wearing a traditional kaross, refusing to call any witnesses, and turning his plea of mitigation into a political speech. Found guilty, he was sentenced to five years' imprisonment; as he left the courtroom, supporters sang Nkosi Sikelel iAfrika.
On 11 July 1963, police raided Liliesleaf Farm, arresting those they found there and uncovering paperwork documenting MK's activities, some of which mentioned Mandela. The subsequent Rivonia Trial began at Pretoria Supreme Court on 9 October, with Mandela and his comrades charged with four counts of sabotage and conspiracy to violently overthrow the government.
Their chief prosecutor was Percy Yutar, who called for them to receive the death penalty. Judge Quartus de Wet soon threw out the prosecution's case for insufficient evidence, but Yutar reformulated the charges, presenting his new case from December until February 1964, calling 173 witnesses and bringing thousands of documents and photographs to the trial.
With the exception of James Kantor, who was innocent of all charges, Mandela and the accused admitted sabotage but denied that they had ever agreed to initiate guerilla war against the government. They used the trial to highlight their political cause; one of Mandela's speeches – inspired by Castro's "History Will Absolve Me" speech – was widely reported in the press despite official censorship. The trial gained international attention, with global calls for the release of the accused from such institutions as the United Nations and World Peace Council. The University of London Union voted Mandela to its presidency, and nightly vigils for him were held in St. Paul's Cathedral, London.
Taken from: http://en.wikipedia.org/wiki/Nelson_Mandela#Arrest_and_Rivonia_trial [12.06.2014]