Muhammad Ali, the magnificent heavyweight champion whose fast fists and irrepressible personality transcended sports and captivated the world, has died. He was 74.

Ali suffered for years from Parkinson's disease, which ravaged his body but could never dim his larger-than-life presence. A towering figure in his prime, he still traveled and made appearances in his later years despite being muted by the thousands of hits he took during his remarkable career.

He was hospitalized in Phoenix with respiratory problems earlier this week, and his family gathered around him. He died Friday night, according to a statement from the family.

Ali was a giant of his time — a furious and loud fighter whose influence was felt far beyond the ring. He engaged in some of the world's most iconic fights even though his career was interrupted for more than three years when he refused to be drafted for military service during the Vietnam War.

He beat the invincible Sonny Liston, fought a string of thrilling fights with Joe Frazier and stopped George Foreman in the "Rumble in the Jungle" in Zaire. But he paid a terrible price for the estimated 29,000 punches he took to his head during a career that made him perhaps the most recognized person on earth.

"I am the greatest," Ali thundered again and again.

Few would disagree.

Despite his debilitating illness, he traveled the world to rapturous receptions even as the once-bellowing voice was reduced to a whisper and he was left to communicate with a wink or a weak smile.

Revered — and reviled — by millions, Ali cut quite a figure in his prime, indeed, complete with an entourage nearly as colorful as he was urging him to "float like a butterfly, sting like a bee." He finished with a record of 56-5 with 37 knockouts and was the first man to win heavyweight titles three times.

But his life outside the ring was as fascinating — and controversial — as his life inside the ropes.

Ali spurned white America when he joined the Black Muslims and changed his name from Cassius Clay to Muhammad Ali. He defied the draft at the height of the Vietnam war — "I ain't got no quarrel with them Viet Cong" — and lost 3 1/2 years from the prime of his career. He entertained world leaders, once telling Philippines President Ferdinand Marcos: "I saw your wife. You're not as dumb as you look."

The quiet of Ali's later life was in contrast to the roar of a career that had breathtaking highs as well as terrible lows. He exploded on the public scene in the 1960s with a series of nationally televised fights that gave the public an exciting new champion and entertained millions as he sparred verbally with the likes of bombastic sportscaster Howard Cosell in interviews.

Ali once estimated he had made $57 million in his pro career, but the effect of the punches lingered long after most of the money was gone. That didn't stop him from traveling tirelessly to promote Islam, meet with world leaders and champion legislation dubbed the Muhammad Ali Boxing Reform Act, meant to protect fighters from being exploited by managers and promoters. While slowed in recent years, he still was able to make numerous appearances, including a trip to Ireland in 2009.

Despised by some for his outspoken beliefs and refusal to serve in the U.S. Army in the 1960s, an aging Ali became a poignant figure whose attendance at a sporting event would draw long standing ovations.

With his face nearly frozen from the disease and his hands trembling, he lit the Olympic torch for the 1996 Atlanta Games in a performance as riveting as some of his fights —namely, the "Rumble in the Jungle" and the "Thrilla in Manila."

A few years after that, he sat mute in a committee room in Washington, his mere presence enough to persuade lawmakers to pass the boxing reform bill that bore his name.

Born Cassius Marcellus Clay on Jan. 17, 1942, in Louisville, Kentucky, Ali began boxing at age 12 after his new bicycle was stolen and he vowed to policeman Joe Martin that he would "whup" the person who took it.

He was only 89 pounds at the time, but Martin began training him at his boxing gym, the beginning of a six-year amateur career that ended with the light heavyweight Olympic gold medal in 1960.

Ali promised to shock the world by beating the fearsome Liston in 1964 and he did just that to become heavyweight champion for the first time. He dominated the heavyweight ranks until he was stripped of his right to fight for a living when he refused to be inducted for the draft in 1967.

By the time Ali was able to return to the ring following his enforced layoff, he was bigger than ever. Soon he was in the ring for his first of three epic fights against Frazier, with each fighter guaranteed $2.5 million in boxing's first megabucks match.

Before the fight, Ali called Frazier an "Uncle Tom" and said he was "too ugly to be the champ." His gamesmanship could have a cruel edge, especially when it was directed toward Frazier.

In the first fight, though, Frazier had the upper hand. He relentlessly wore Ali down, knocking him down in the 12th round and winning a decision.

It was the first defeat for Ali, but the boxing world had not seen the last of him and Frazier in the ring. Ali won a second fight, and then came the "Thrilla in Manila" on Oct. 1, 1975, in the Philippines, a brutal bout that Ali said afterward was "the closest thing to dying" he had experienced.

Ali won that third fight but took a terrific beating from the relentless Frazier before trainer Eddie Futch kept Frazier from answering the bell for the 15th round. It was, most in boxing agreed, Ali's last great performance, though he would come back to win the heavyweight title from Leon Spinks to make history by winning the heavyweight title for the third time.