27 May 1963
27 May, 2013 marked for 50th anniversary of Nelson Mandela arriving on Robben Island as prisoner. On 5 August they were stopped and arrested just outside the Natal midlands town of Howick. It was alleged that the police were informed of Mandela’s movements by an American CIA agent based in Durban. Mandela was tried in Pretoria's Old Synagogue and in November 1962 sentenced to five years' imprisonment for incitement and illegally leaving the country. He was imprisoned at Pretoria Central Prison where he met his old friend and political opponent Robert Sobukwe, the leader of the breakaway PAC. Mandela spent seven months at Pretoria Central Prison before he was transferred to Robben Island.
References

South African History Online, ‘Nelson Rolihlahla Mandela’, [online], available at www.sahistory.org.za (Accessed: 27 May 2013)|

O’Malley, P. ‘1963’, from Nelson Mandela Centre of Memory, [online], available at www.nelsonmandela.org.za (Accessed: 27 May 2013)