His release on Feb. 11, 1990, would mark a new beginning for the country and the slow end for the segregationist system imposed by the white minority government.
Mandela had joined the African National Congress, a black political organization, in the 1940s and eventually created the group's armed wing after the 1960 massacre of peaceful black protesters.
In 1964, he was handed down a life sentence on sabotage charges. Most of his time served occurred at the Robben Island prison, where he was confined to a small cell and forced into hard labor.
He was released in 1990 after South African President F.W. de Klerk lifted a ban on the ANC and ordered him to be free. Apartheid ended and a multiracial government took hold.
Four years later, Mandela became South Africa's first black president after the ANC received an electoral majority in South Africa's first free elections.
He shared the 1993 Nobel Peace Prize with de Klerk. Mandela stepped down after one term as president and later died in 2013 at age 95.