One of the world’s best-known sportsmen, boxing legend Muhammad Ali, has died at the age of 74, a family spokesman has confirmed.

The former world heavyweight boxing champion died at a hospital in Phoenix, Arizona, after being admitted on June 2.

Muhammad Ali was suffering from a respiratory illness, a condition that was complicated by Parkinson’s disease.

The funeral will take place in his hometown of Louisville, Kentucky, his family said in a statement.

Born Cassius Marcellus Clay, Muhammad Ali shot to fame by winning light-heavyweight gold at the 1960 Rome Olympics.

Nicknamed “The Greatest”, he beat Sonny Liston in 1964 to win his first world title and became the first boxer to capture a world heavyweight title on three separate occasions.

Muhammad Ali eventually retired in 1981, having won 56 of his 61 fights.

Crowned “Sportsman of the Century” by Sports Illustrated, Muhammad Ali was noted for his pre- and post-fight talk and bold fight predictions just as much as his boxing skills inside the ring.

He was also a civil rights campaigner and poet who transcended the bounds of sport, race and nationality.

Asked how he would like to be remembered, Muhammad Ali once said: “As a man who never sold out his people. But if that’s too much, then just a good boxer. I won’t even mind if you don’t mention how pretty I was.”

Muhammad Ali turned professional immediately after the Rome Olympics and rose through the heavyweight ranks, delighting crowds with his showboating, shuffling feet and lightning reflexes.

British champion Henry Cooper came close to stopping Cassius Clay, as he was still known, when they met in a non-title bout in London in 1963.

Henry Cooper floored Cassius Clay with a left hook, but Clay picked himself up off the canvas and won the fight in the next round when a severe cut around Cooper’s left eye forced the Englishman to retire.

In February 1964, Cassius Clay stunned the boxing world by winning his first world heavyweight title at the age of 22.

He predicted he would beat Sonny Liston, who had never lost, but few believed he could do it.

Yet, after six stunning rounds, Sonny Liston quit on his stool, unable to cope with his brash, young opponent.

At the time of his first fight with Sonny Liston, Cassius Clay was already involved with the Nation of Islam, a religious movement whose stated goals were to improve the spiritual, mental, social, and economic condition of African Americans in the US.

In contrast to the inclusive approach favored by civil rights leaders like Dr. Martin Luther King, the Nation of Islam called for separate black development and was treated by suspicion by the American public.

Muhammad Ali eventually converted to Islam, ditching what he perceived was his “slave name” and becoming Cassius X and then Muhammad Ali.

In 1967, Muhammad Ali took the momentous decision of opposing the US war in Vietnam, a move that was widely criticized by his fellow Americans.

Muhammad Ali refused to be drafted into the US military and was subsequently stripped of his world title and boxing license. He would not fight again for nearly four years.

After his conviction for refusing the draft was overturned in 1971, Muhammad Ali returned to the ring and fought in three of the most iconic contests in boxing history, helping restore his reputation with the public.

Muhammad Ali was handed his first professional defeat by Joe Frazier in the “Fight of the Century” in New York on March 8, 1971, only to regain his title with an eighth-round knockout of George Foreman in the “Rumble in the Jungle” in Kinshasa, Zaire (now Democratic Republic of Congo) on October 30, 1974.

He fought Joe Frazier for a third and final time in the Philippines on October 1, 1975, coming out on top in the “Thrilla in Manila” when Frazier failed to emerge for the 15th and final round.

Six defenses of his title followed before Muhammad Ali lost on points to Leon Spinks in February 1978, although he regained the world title by the end of the year, avenging his defeat at the hands of the 1976 Olympic light-heavyweight champion.

Muhammad Ali’s career ended with one-sided defeats by Larry Holmes in 1980 and Trevor Berbick in 1981, many thinking he should have retired long before.

He fought a total of 61 times as a professional, losing five times and winning 37 bouts by knockout.

Soon after retiring, rumors began to circulate about the state of Muhammad Ali’s health. His speech had become slurred, he shuffled and he was often drowsy.

Parkinson’s Syndrome was eventually diagnosed but Muhammad Ali continued to make public appearances, receiving warm welcomes wherever he travelled.

Muhammad Ali lit the Olympic cauldron at the 1996 Games in Atlanta and carried the Olympic flag at the opening ceremony for the 2012 Games in London.