Muhammad Ali had a pioneering career both in and out of the boxing ring. He won the gold medal at the 1960 Olympics and became the world heavyweight champion in 1964 by defeating Sonny Liston. Ali joined the Nation of Islam in 1964 and changed his name from Cassius Clay to Muhammad Ali, which was controversial at the time. In 1967, Ali refused induction into the military due to his religious beliefs, which led to him being stripped of his title and sentenced to prison. Though banned from boxing for three years, Ali continued fighting for social justice and inspiring others with his courage and principles.