He initially upheld nonviolent resistance, but later on Mandela decided that violent protest was necessary to end racial oppression.
At first, he advocated non-violent resistance to apartheid. But the white government's brutal suppression of protestors led Mandela to change his stance. He abandoned his non-violent position after government troops murdered 69 black protestors in Sharpeville in 1960.
"There are many people who feel that it is useless and futile for us to continue talking peace and non-violence against a government whose reply is only savage attacks on an unarmed and defenseless people," he expressed at the time.
