I wouldn't call Mandela a champion of peace, but of freedom.
Mandela was in prison for 27 years, oppressed his whole life before and after that, and once he gets power, his watchwords? Truth and Reconciliaton.
That's why he deserved the Nobel Peace Prize, because with any other leader (just pick a country on the same continent, Zimbabwe's right next door) that situation turns into a shitshow at that point.
The fact that he was in the ANC isn't what makes him notable, plenty of other guerilla leaders in Africa who threw out colonialists or white minority rule. That's not why we're talking about him. What he did when he won made him notable.
The "he wasn't peaceful" idiots on this thread are either incapable of seeing the big picture or fighting some dumb US domestic political battle.
(I don't think the Rhodesia precedent was exact, as the white rulers of Rhodesia were probably far more acceptable, and blacks far less oppressed, than they were in RSA; RSA was sufficiently self-sufficient that this could have gone on indefinitely. The other cases were anti-colonialism, which is also different; the Boers were not particularly tied to any European power, so there was no European state pulling out to end the colonial situation, either.)
Did I get that right?
Blowing up civilians is probably required at times, I don't know, but the exact border line where it moves from acceptable to unacceptable is a difficult one. Some people (justly) hold that it is always unacceptable and there is definitely nothing wrong with that stand. Others are more pragmatic and can accept that killing 10 civilians is preferable to having 10,000 slaves.
It's not an easy answer, don't dismiss it as an ad hominem.