This person is a legend. His countrymen used to call him Madiba meaning brother.
Nelson Mandela was an ardent follower of Mahatma Gandhi and his ideology of non-violence.
The greatness of this man cannot be summed up in just few lines..
There is movie named "Invictus" on Mandela, a very very good and truly inspirational movie.
You can watch this movie. I am pretty sure, your respect and admiration for this great person will very much become more.