Cassius Clay, the greatest boxer in the world, was born in America in 1942. He was well-behaved, he had good manners and his teachers liked him. In 1954, Joe Martin, a policeman, taught him how to box. In six years, he had 108 fights and won 100 of them. In 1960, he won the gold medal in boxing in the Olympic Games in Rome, although he was only eighteen years old. After he had become a world championship, he became Muslim and changed his name to Muhammad Ali. Since then, he was called the king of championships. By 1980, Ali was getting old. Doctors advised him to stop boxing and he retired. Now he works for children's charities.