Before he was sentenced, he made a famous "speech from the dock," which ends with the words - in reference to his ideals and his country - "I am prepared to die."
The Mandela Foundation describes the trial this way:
In the Rivonia Trial Mr Mandela chose, instead of testifying, to make a speech from the dock and proceeded to hold the court spellbound for more than four hours. His speech, which was made at the beginning of the defence case, ended with the words:
"During my lifetime I have dedicated myself to this struggle of the African people. I have fought against white domination, and I have fought against black domination. I have cherished the ideal of a democratic and free society in which all persons live together in harmony and with equal opportunities. It is an ideal which I hope to live for and to achieve. But if needs be, it is an ideal for which I am prepared to die."
The full speech transcript is here.
Mandela (with Walter Sisulu, Govan Mbeki, Raymond Mhlaba, Elias Motsoaledi, Andrew Mlangeni, Ahmed Kathrada and Denis Goldberg) were sentenced to life in prisonment. Mandela spent the better part of the next three decades as a prisoner on Robben Island.
Upon his release in 1990, a day that was the beginning of the end of apartheid, Mandela made another famous speech, in front of 100,000 people in Johannesburg. It was broadcast live around the world. For most people, it was the first time they had seen or heard Mandela since the early 1960s.