Muhammad Ali would have turned 80 this year.
One of boxing's greatest, an activist and a philanthropist, it's quite fitting his birthday falls on Martin Luther King Jr Day (January 17).
To celebrate, Planet Sport has decided to look into 50 facts about 'The Greatest'.
1) Aside from Michael Jordan, no athlete has more Sports Illustrated covers than Muhammad Ali (54).
2) Muhammad Ali won light heavyweight gold at the 1960 Olympics in Rome.
3) After his homecoming to celebrate Olympic glory, Ali - known as Cassius Clay at the time - threw his gold medal into the Ohio River after a restaurant refused to serve him because of his skin colour.
4) Ali is a former three-time heavyweight champion. His world title wins came against Sonny Liston (1964), George Foreman (1974) and Leon Spinks (1978).
5) In 1976, after his win over Joe Frazier, Muhammad Ali had a crossover exhibition fight against Japanese wrestler Antonio Inoki. The rules were unspecified but in later years, Ali was credited for introducing the arrival of MMA.
6) After fighting Antonio Inoki, Ali had two blood clots in his leg and nearly had it amputated.
7) Due to his reluctance to fight in the Vietnam War, Muhammad Ali was refused a boxing license between 1967 and 1970. Ali's first fight back was at the age of 29.
8) His daughter Laila Ali is a former female boxer and retired as an undefeated world champion. His grandson, Nico Ali Walsh, is also now fighting, under the Top Rank banner.
9) Muhammad Ali never consumed alcohol or smoked a cigarette in his life.
10) During his ban from boxing, Muhammad Ali starred in a Broadway musical that ran for one week.
11) Columbia Records released Ali's album I Am the Greatest in August 1963.
12) Georgia State granted Ali a boxing license in 1970.
13) Ali's 1970 comeback fight was against Jerry Quarry, who he knocked out in three rounds.
14) Ali's mother was a domestic helper and his father was a billboard painter.
15) In 1964, he changed his name from Cassius Clay to Muhammad Ali after joining the Nation of Islam.
16) In 1971, Joe Frazier inflicted the first defeat of Muhammad Ali's career via unanimous decision.
17) Muhammad Ali competed in the ring against Joe Frazier on three occasions.
18) Muhammad Ali and Joe Frazier's third fight is regarded as one of the most famous fights of all-time - the Thrilla in Manila. Ali won via TKO before round 15.
19) Muhammad Ali's Rumble in the Jungle clash with George Foreman is believed to have generated an audience of more than one billion people worldwide.
20) Following his victory against Leon Spinks in 1978, Ali became the first boxer to win the world heavyweight boxing titles three times.
21) Muhammad Ali was married four times and had seven daughters and two sons.
22) In the 1996 opening ceremony for the Atlanta Summer Olympics, Muhammad Ali had the honour of lighting the cauldron.
23) In 1999, Muhammad Ali was named BBC's 'Sporting Personality of the Century'.
24) Muhammad Ali was named by Ring Magazine as 'the Fighter of the Year' on five occasions.
25) In 1990, he was inducted into the International Boxing Hall of Fame.
26) Muhammad Ali took up boxing at the age of 12
27) Muhammad Ali won his debut professional boxing fight via unanimous decision against Tunney Hunsaker on October 29, 1960.
28) Muhammad Ali lost five professional fights in his career - Larry Holmes, Trevor Berbick, Leon Spinks, Ken Norton and Joe Frazier.
29) He formed his own promotional company called Main Events.
30) Muhammad Ali was co-promoted by Bob Arum in 27 fights of his career.
31) He fought in the UK three times, defeating Henry Cooper (twice) and Brian London.
32) Muhammad Ali knocked out Sonny in the first round of their rematch on May 25, 1965.
33) Convicted of evasion of draft, Muhammad Ali was imposed with a fine of $10,000 and to a maximum of five years in prison. He avoided a jail term.
34) Muhammad Ali was Mike Tyson's hero.
35) Cassius Clay won two national Amateur Athletic Union titles, two national Golden Glove titles, and 100 victories before fighting at the Olympics.
36) Muhammad Ali was named Sports Illustrated Sportsman of the Century in 1999.
37) Prior to becoming heavyweight world champion, the American won 15 of his first 19 inside the distance.
38) "Float like a butterfly, sting like a bee" is one of many lines Muhammad Ali said to earn his nickname as the Louisville Lip.
39) Muhammad Ali's fight against Leon Spinks in New Orleans in 1978 saw an indoor record attendance of 63,352. The record was eventually broken by Canelo Alvarez vs Billy Joe Saunders in 2021.
40) Photographer Howard Bingham was Ali's best friend for 35 years and travelled all over the world with him.
41) Some of his close friends were from the celebrity world, including Denzel Washington and Magic Johnson.
42) Muhammad Ali had four wives: Sonji Roi (m. 1964; div. 1966), Belinda Boyd (m. 1967; div. 1977), Veronica Porche Ali (m. 1977; div. 1986), and Yolanda Williams (m. 1986).
43) His nine children are: Laila, Maryum, Asaad, Rasheda, Hana, Jamillah, Miya, Khaliah, and Muhammad Ali Jr. He also had a brother, Rahman Ali.
44) DC Comics published Superman vs. Muhammad Ali in 1978 - an oversize comic in which Muhammad Ali saves the world by defeating Superman.
45) In real life, Muhammad Ali saved a man from suicide from the ninth story of a building in Los Angeles.
46) Muhammad Ali loved to eat hot buttered bread rolls, macaroni and cheese, green peas, spinach and cooked chicken.
47) Muhammad Ali's footwork is believed to have inspired martial artist and actor Bruce Lee.
48) After a near four year lay-off, Muhammad Ali returned to the ring as a different fighter. Gone was his natural athleticism and movement around the ring.
The physical change saw him adopt a rope-a-dope technique. Ali would stay on the ropes, absorb punches and then counterpunch once his opponent ran out of steam. The tactics were proved a huge success, especially against George Foreman.
49) In total, an estimated 9.6 billion people tuned in to watch his boxing career on TV.
50) Muhammad Ali was part of the first Wrestlemania event. He was the special guest referee for a tag team match that included Hulk Hogan, Mr T, Jimmy Snuka, 'Rowdy' Roddy Piper and 'Mr Wonderful' Paul Orndorff.