TIMELINE

Early life
January 17, 1942: Cassius Marcellus Clay Junior is born in Louisville, Kentucky.
December 1954: In Clay's ring debut as an 89-pound amateur, he takes a three-round split decision over Ronnie O'Keefe.

1960s
1960: Wins Olympic light heavyweight title with victory over three-time European Champion Zbigniew Pietrzykowski of Poland in the final.
October 29, 1960: Wins six-round decision over Tunney Hunsaker in his professional debut in Louisville
February 25, 1964: Upsets Sonny Liston to win the heavyweight world title.
March 6, 1964: Embraces the Nation of Islam and takes the name Muhammad Ali.
May 25, 1965: Knocks out Liston at 1:52 of the first round of their world championship rematch.
May 8, 1967: Ali indicted in Houston for refusing induction into the army and is stripped of his boxing title.
June 1967: Ali is convicted of draft dodging and sentenced to five years in prison, fined $10,000 and forced to surrender his passport.

1970s
February 3, 1970: Thwarted in efforts to resume his career, announces retirement.
September 2, 1970: Returns to ring after absence of more than three years in exhibition bouts.
October 26, 1970: Returns to the ring against Jerry Quarry in Atlanta.
December 30, 1970: Signs to meet Joe Frazier for the heavyweight title. Each fighter is to receive an unprecedented $2.5 million. 
March 8, 1971: Loses close 15-round decision to Frazier, his first professional defeat.
June 28, 1971: US Supreme Court reverses  draft-dodging conviction.
October 30, 1974: Regains the world heavyweight title with upset of unbeaten George Foreman in Kinshasa, Zaire.
October 1, 1975: The "Thrilla in Manila", an epic contest between Ali and Frazier ends when Frazier fails to answer bell for 15th round.
October 1, 1976: Ali retires for the second time, a decision he reversed two months later.
February 15, 1978: Leon Spinks upsets Ali in 15 rounds to claim the world title.
September 15, 1978: Ali becomes the first three-time heavyweight world champion with a victory over Spinks.
June 27, 1979: Announces retirement for the third time, saying, "I'd be a fool to fight again."

1980s
April 28, 1980: Announces bout with Larry Holmes for October 1980. 
October 2, 1980: Holmes pounds Ali to win vacant heavyweight title.
December 11, 1981: Beaten by Trevor Berbick. Ali's last pro fight. "I feel 40 years old," Ali said. "It's the end."
September 19, 1984: Undergoes tests that diagnose Parkinson's disease.

1990s
July 19, 1996: Lights Olympic cauldron at opening of Atlanta Olympics to international acclaim.