7 November 1962
Nelson Mandela was identified as the "mouthpiece and mastermind" behind a call for a national strike and the formation of Umkhonto we Sizwe (Spear of the Nation). Mandela founded Umkhonto we Sizwe (MK) with the intention to prepare for an armed struggle against the apartheid government. In 1962 He was smuggled out of South Africa to speak at an African freedom conference in Addis Ababa. Shortly after his return, he was arrested and charged with leaving the country illegally and incitement to strike. Bob Hepple acted as his legal representitive. He was subsequently sentenced to five years in prison. In a turn of events, the following year he was charged with treason along with 10 other accused following the government’s discovery of Liliesleaf Farm, the head quarters of MK. The trial, which was dubbed the ‘Rivonia Trial’, lasted eight months.  Mandela was found guilty and sentenced to life imprisonment. He was flown to Robben Island immediately after the trial to start serving his sentence.
References

Nelson Mandela.org (2011).’ Biography’ from Nelson Mandela .org [online] Available at: www.nelsonmandela.org [Accessed on 11 October 2011]|Thefamouspeople.com (2011). ‘Nelson Mandela’ from Famous People [online] Available at: www.thefamouspeople.com  [Accessed on 11 October 2011]| Hepple, B. Rivonia: The Story of Accused No 11,‘The Road to Rivonia: July 11 1963’, (1999) pg 8