Muhammad Ali was a boxer who made headlines in and out of the ring.
Famous for his fast footwork and even quicker mouth, he is known as one of the greatest sportspeople of all time.
Where was he from?
Muhammad Ali was born on 17 January 1942, in Kentucky, USA.
However, he was originally called Cassius Clay. He changed his name in 1964 after joining a religious group called the Nation of Islam.
Fighting as Cassius Clay, he won the Light Heavyweight gold medal at the 1960 Olympics. He then began his professional career.
He won his first world title in 1964, at age of 22, beating Sonny Liston in a fight few experts thought he could win.
By the end of Ali's boxing career he had won the World Heavyweight Championship three times.
Probably his most famous fight was against George Foreman, known as the Rumble in the Jungle. It took place on 30 October 1974 in the African country Zaire (now called the Democratic Republic of the Congo).
Foreman went into the match as favourite to win. He was the world champion and had never lost a fight.
But Ali beat him with some clever tactics and brilliant boxing. He allowed himself to be hit in places where it didn't hurt too much, tiring the younger fighter out.
In the eighth round Ali began to attack, and knocked Foreman down to regain the world title.
Ali was stripped of his boxing license and got in trouble with the law when he refused to fight in the Vietnam War in 1967.
The courts later decided he didn't have to go to war, so he was allowed to box again.
Ali was well known for being quick-witted. Here are a few of his most famous lines.
- Describing how he would fight Sonny Liston, he said he would "float like a butterfly and sting like a bee."
- "I am the greatest. I said that even before I knew I was."
- "I'm so fast that last night I turned off the light switch in my hotel room and was in bed before the room was dark."
- "It's hard to be humble, when you're as great as I am."