Mandela contributed to the freedom struggle of his people. He joined the African National Congress in 1944 and became engaged in resistance against the ruling National Party. On June 12, 1964, Mandela was sentenced to life imprisonment and was released on February 11, 1990. He was elected President of South Africa. Check out http://www.nobelprize.org/nobel_prizes/peace/laureates/1993/mandela-bio.html for more information.