As Cassius Clay, he won a light heavyweight gold medal at the 1960 Olympics and began his ascent to the heavyweight crown. On the way up he beat Billy Daniels, Archie Moore, Doug Jones and Henry Cooper.
In 1964, he challenged the seemingly indomitable Sonny Liston for the heavyweight title. A significant underdog, Clay indeed "Shocked the World" by forcing Liston to retire on his stool after the sixth round. After the fight Clay announced that he accepted the teachings of Islam and changed his name to Muhammad Ali.
Ali was both arrogant and charismatic and generated a wide range of emotions from those who loved him and hated him. He often predicted the round in which he would win and wrote poetry describing how he would defeat opponents. So talented and so fast was Ali, that he was able to box while holding his left hand by his side and often pulled straight back to avoid punches, two of the game's cardinal sins. Nonetheless, he employed the best jab in boxing and had handspeed comparable to a welterweight.
Then in 1967, Ali, citing his religous beliefs, refused induction into the U.S. Army. He was arrested, had his boxing license suspended and stripped of the heavyweight title. He was inactive from March 22, 1967 to October 26, 1970, which many feel were his peak years.
With Ali gone, Joe Frazier tore through the division and earned the title of heavyweight champion. Ali returned in 1970 with wins over Jerry Quarry and Oscar Bonavena, setting up a showdown between Ali and Frazier.
Both men were unbeaten and while Frazier earned his heavyweight title in the ring, Ali proclaimed himself the peoples' champion and that Frazier must beat him to become undisptuted king of the division. He did just that. In what is still called "The Fight of the Century," Frazier dropped Ali in the 15th round and won a unanimous decision.
Ali regained the heavyweight crown in 1974 much the way he initially captured the title, by slaying a giant. George Foreman was considered invincible and the 32-year-old Ali was given little chance to beat him. The fight was held in Kinsasha, Zaire and Ali employed the now famous Rope-A-Dope to tire Foreman out before stopping him in the eighth round.
Ali successfully defended the title against a host of contenders, including the final fights of his trilogies with Frazier and Ken Norton. Finally, in 1978, Olympic gold medalist Leon Spinks, participating in just his eighth pro fight, upset Ali to win the title. However, Ali made history six months later when he defeated Spinks in a rematch to capture the crown a third time.
Far past his prime, Ali had two more fights and both ended in defeat. He was stopped by Larry Holmes, a former sparring partner and then the WBC heavyweight champion, in 1980 and lost a 10-round decision to future champ Trevor Berbick in 1981.
Taken from www.ibhof.com/ali.htm