(CNN) His hands and his mouth were furiously fast. His skill as a boxer made him "The Greatest" in his mind and in the minds of many others.

He antagonized opponents with his taunts, amused reporters with his boasts and angered government officials with his anti-war speeches. At the same time, he goaded a stubborn, hard-nosed society with his stinging jabs against pervasive racism.

Since the mid-1960s, he was one of the most famous faces on Earth, and even though his appearances in recent years were few, the name Muhammad Ali still sparked smiles all around the globe.

His death Friday at age 74 came after a lengthy battle against Parkinson's disease. Ali was diagnosed with the disease in 1984, three years after he retired from a boxing career that began when a skinny 12-year-old Louisville, Kentucky, amateur put on the gloves.

He is survived by his nine children, including daughter Laila, who, like her father, became a world champion boxer; and his fourth wife, Lonnie.

Ali was known in the ring for his lightning hand speed -- unusual for a heavyweight -- for his showmanship and for his brashness and braggadocio when a microphone was put before him. He taunted opponents before matches, trash-talked them during and proclaimed his greatness to reporters afterward.

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He stayed on his toes, literally, during a bout, sometimes quickly moving his feet forward and backward while his upper body stayed in place. The mesmerizing move became known as the "Ali Shuffle."

Fans on every continent adored him, and at one point he was the probably the most-recognizable man on the planet.

But he also was a controversial figure at home, announcing his conversion to Islam and name-change after an upset title win over Sonny Liston, then refusing to enter the draft for the Vietnam War and publicly speaking about racism in the United States.

In youth, told he'd better learn to box

Ali was born January 17, 1942, in Louisville as Cassius Marcellus Clay Jr. His interest in boxing began at age 12, after he reported a stolen bike to a local police officer, Joe Martin, who was also a boxing trainer.

Martin told the young, infuriated Clay that if he wanted to pummel the person who stole his bike, he had better learn to box.

Over the next six years, Clay won six Kentucky Golden Gloves championships, two National Golden Gloves championships and two National Amateur Athletic Union titles.

Just months after he turned 18, Clay won a gold medal as a light heavyweight at the 1960 Olympic Games in Rome, convincingly beating an experienced Polish fighter in the final.

The story goes that when he returned to a hometown parade, even with the medal around his neck, he was refused service in a segregated Louisville restaurant because of his race. According to several reports, he threw the medal into a river out of anger. The story is disputed by people who say Ali misplaced the medal.

Thirty-six years later, he was given a replacement medal and asked to light the cauldron at the 1996 Olympic Games in Atlanta, something he said was one of the greatest honors in his athletic career.

Clay turned professional after the 1960 Olympics and quickly won 19 straight fights. For many of them, Clay -- then known as "The Louisville Lip" -- would make a rhyme to predict in what round his opponent would fall.

The underdog stings like a bee

For his first heavyweight title fight, against the brutish Liston in 1964, he went a step further, renting a bus, and on the day he signed to fight the champ he went by Liston's home.

On the side of the bus was painted: "World's Most Colorful Fighter" and "Liston Will Go In Eight." To make sure he was heard, Clay used a megaphone and shouted from an open window.

And in the lead-up to the fight, Clay, flanked by corner man Drew "Bundini" Brown, uttered the famous phrase that followed him forever, "Float like a butterfly, sting like a bee." (Often missed is the subsequent line, "Rumble, young man, rumble.")

In stark contrast to Clay's pretty-boy image, Liston -- a formidable and domineering fighter -- had an extensive criminal past. He learned to box in prison. But the young, brash Clay appeared supremely confident, and his mocking of Liston was relentless.

"The crowd did not dream when they laid down their money that they would see the total eclipse of the Sonny," he said.

Despite the 7-to-1 odds against him, Clay defeated Liston in seven rounds to become heavyweight champion of the world.

He later told CNN's Nick Charles that, despite his bravado, he was "scared to death."

"I just acted like I wasn't," he said.

Post-Liston: From Cassius X to Muhammad Ali

The day after the Liston fight, Clay announced that he had joined the Nation of Islam and was changing his name to Cassius X, the letter symbolizing the unknown name taken away from his family by slave owners hundreds of years before.

A year later, he was anointed Muhammad Ali by Nation of Islam leader Elijah Muhammad. Most sportscasters initially refused to call him by his new name. But Howard Cosell did, becoming a supporter and friend to the champ as they verbally sparred for the rest of Cosell's life.

Once Cosell said Ali was being truculent.

Ali snapped back, "Whatever truculent mean, if that's good, I'm that."

Many in the United States scorned Ali's name change and his alignment with the Nation of Islam, and a furor erupted after he refused, because of his religious beliefs, to serve in the military during the Vietnam War when he was called up in 1966.

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"I ain't got no quarrel with them Viet Cong," Ali said. "No Viet Cong ever called me n----r."

At the weigh-in before one of his last fights of 1967, his opponent, Ernie Terrell, called him "Clay."

A furious Ali trounced Terrell in the ring while yelling "What's my name?" A month later, Ali knocked out Zora Folley.

But, at the peak boxing age of 26, he began a forced three-and-a-half-year exile from championship boxing.

The conscientious objector

Almost as quickly as Ali had arrived, his World Boxing Association heavyweight title was gone, revoked after he claimed conscientious objector status in refusing the draft. He also was stripped of his passport and all of his boxing licenses. He faced a five-year prison term after losing an initial court battle defending his objection to serving in a war that he called "despicable and unjust."

Ali lost the chance at tens of millions of dollars in endorsements while appealing his case to the U.S. Supreme Court.

During this time, Ali aligned himself with Nation of Islam leaders including Malcolm X, making him even more of a controversial figure as well as a household name.

He earned a living during his hiatus from boxing by speaking against the Vietnam War on college campuses, one of the first national figures to verbally oppose the war.

"What was so important about it was that in a war in which young black men, mainly without any money and with little education, were dying in disproportionate numbers and being shipped off to Southeast Asia in disproportionate numbers, the symbol of strength, the symbol of vitality and virility, this young black man -- outspoken -- stands up and says 'no,'" explained David Remnick, author of "King of the World," a book about the young boxer.

Back to the ring -- and on to Joe Frazier

The anti-war sentiment had gathered momentum by 1970, when a judge ruled that Ali could box professionally. When Ali made his return to the ring, he discovered that the long absence had left a marked effect on his skills.

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He quickly dispatched Jerry Quarry in his first fight back, but had a rough 15-round go with Oscar Bonavena before he got a chance to reclaim his title.

In 1971, he and his perfect record met undefeated champion Joe Frazier in an epic battle that boxing writers have dubbed "The Fight of the Century." Each man was guaranteed $2.5 million, at that time the biggest boxing payday in the sport, with an estimated 300 million viewers worldwide.

Their rivalry would become legend and intensely personal, with constant verbal taunting from Ali.

"I'll be the ghost that haunts boxing," he said. "People will say, 'Ali is the real champ, and everyone else is a fake,'" Ali said of Frazier.

Ali also hurled racial insults at Frazier, calling him an "Uncle Tom" and a black man disguised as a Great White Hope, a phrase that Frazier later said infuriated him.

And Ali delighted the media when he proclaimed, "Joe is going to come out smoking, but I ain't going to be joking. I'll be pecking and a-poking, pouring water on his smoking. This might shock and amaze ya, but this time I'll retire you, Frazier."

The world would soon learn that even the man who called himself "The Greatest" had his struggles. The match began with both fighters engaging in a series of powerful punches and counterattacks. In the 15th round, Frazier unleashed a devastating left hook that floored Ali.

It would be only the third time Ali had been knocked down in his career. When the final bell rang, the judges awarded Frazier a 15-round decision, sending Ali to his first loss in 32 professional fights.

Months after the defeat, Ali got a major victory outside the ring when the U.S. Supreme Court upheld his conscientious objector claim. His passport and his boxing licenses were reinstated, and the threat of prison time was erased.

Over the next few years, Ali's religious views turned him more toward Sunni Islam, and he rejected many of the teachings of the Nation of Islam.

He won a 1974 rematch with Frazier, earning another shot at the heavyweight title, which would turn out to be the fight of his career and one of the most memorable events in sports history.

Foreman, Zaire and 'The Rumble in the Jungle'

"The Rumble in the Jungle" pitted Ali against fearsome champion George Foreman, a 3-to-1 favorite to win the match in central Africa. Boxing promoter Don King had struck an agreement with the government of Zaire to guarantee the unheard-of sum of $10 million for the boxers.

Photos: Rumble in the Jungle: More than 40 years later Photos: Rumble in the Jungle: More than 40 years later Was it the greatest sporting occasion of the 20th century? For many, the world heavyweight championship between Muhammad Ali and George Foreman -- dubbed the "Rumble in the Jungle" -- is the most compelling contest of all time. More than 40 years after this legendary bout, which took place in Kinshasa, Zaire, on October 30, 1974, we look back at a night that went down in history. Hide Caption 1 of 10 Photos: Rumble in the Jungle: More than 40 years later Foreman arrived in Africa as the undefeated world champion, Ali as the challenger. Ali's refusal to fight in the Vietnam War had resulted in a ban from boxing and the stripping of his world title, while Foreman had risen to the top of the sport following a gold medal at the 1968 Olympic Games. "To me, it was like a charity fight," Foreman told the BBC. "I'd heard Ali was desperately broke, so I thought I'd do him a favor. I got $5 million and I was willing to let him have $5 million." Hide Caption 2 of 10 Photos: Rumble in the Jungle: More than 40 years later Both Foreman and Ali arrived in Zaire -- now known as Democratic Republic of Congo -- long before the fight to acclimatise to the conditions in Kinshasa. The fight was staged in Zaire with the aim of boosting tourism in the country, and it was accompanied by a three-day music festival. Hide Caption 3 of 10 Photos: Rumble in the Jungle: More than 40 years later Ali's mother, Odessa Lee Clay, tends to her son three days before the fight. "I always felt like God made Muhammad special," she said of Ali, "but I don't know why God chose me to carry this child." Hide Caption 4 of 10 Photos: Rumble in the Jungle: More than 40 years later The weigh-in for the hotly anticipated bout took place on October 29, 1974. "Big George" Foreman came in at 220 pounds, while the challenger Ali, who at the age of 32 was giving away seven years to his opponent, weighed in at 216. Foreman was the favorite for the fight, with Ali's business manager Gene Kilroy concerned about how he could deal with his friend should the worst happen. "My biggest fear was, suppose Ali got hurt. How good are the hospitals in Zaire? What would we have to do? Go on an aeroplane and get to Paris," Kilroy told British newspaper The Daily Telegraph. "I discussed this with Ali and he said: 'Don't worry about me, worry about George.' " Hide Caption 5 of 10 Photos: Rumble in the Jungle: More than 40 years later A crowd of 60,000 packed into the 20th of May Stadium to see Ali, renowned for "dancing" across the ring, change his tactics for the fight, a move which ultimately undid the powerful Foreman. "The idea it was some premeditated plan is nonsense," renowned British sportswriter Hugh McIlvanney opined. "It was more of a triumph that such a brilliant improvisation had come to him in a crisis." The tactic spawned the expression "rope-a-dope" as Ali lay on the boxing ring's ropes, thereby diminishing the power of Foreman's punching. Hide Caption 6 of 10 Photos: Rumble in the Jungle: More than 40 years later Ali's tactics bamboozled Foreman, who struggled to get on top of the challenger. "He became so confused by Ali's tactics that he finished the fourth round hurling wild swings into the air, and later missed so badly with the punch that was meant to finish it all that he almost went through the ropes," late sportswriter Ian Wooldridge wrote in the Daily Mail. "Ali slapped him on the bottom." Hide Caption 7 of 10 Photos: Rumble in the Jungle: More than 40 years later "I shall be the matador and Foreman the bull," Ali had boasted in the buildup to the fight, and so it proved. The decisive blow came in the eighth round. A flurry of punches ended with a right hand that sent Foreman sprawling to the canvas. Hide Caption 8 of 10 Photos: Rumble in the Jungle: More than 40 years later Before the fight, Ali had famously claimed to have "handcuffed lightning, thrown thunder in jail," while also saying, poetically, "floats like a butterfly, sting like a bee, his hands can't hit what his eyes can't see." Hide Caption 9 of 10 Photos: Rumble in the Jungle: More than 40 years later In the aftermath of the "Rumble in the Jungle," Ali named his price for his next fight. "I'm going to haunt boxing for the next six months," he was reported to have said by the Daily Mail. "I'll talk to the man who first offers me $10 million." A hefty price tag, even for the man dubbed by many, not least himself, as "The Greatest." Hide Caption 10 of 10

Ali adapted his trademark phrase by telling reporters he would "float like a butterfly, sting like a bee, his hands can't hit what his eyes can't see."

Instead, in what is considered to be his best tactical fight, Ali used the "rope-a-dope" technique, leaning far back on the ropes, absorbing Foreman's punches with his gloves and arms and letting the heavy puncher tire out.

All throughout the fight, the throng of fans chanted: "Ali bomaye! Ali bomaye!" which means "Ali, kill him!"

In the eighth round, Foreman swiped at Ali in one corner for more than a minute until a stinging series of Ali right hands sent Foreman to the ground and brought a boisterous roar from the people watching.

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The next year, Ali defeated Frazier again in the Philippines, the famous "Thrilla in Manila," after 14 grueling rounds.

A damaged champ's career winds down

Ali retained his title as heavyweight champ until 1978, when he lost in a shocker to the inexperienced Leon Spinks. After defeating Spinks in a rematch, he regained the title for a record third time, only to give it up when he announced a short-lived retirement in 1979.

He came back the next year at age 38, when he challenged Larry Holmes, hoping to capture a fourth heavyweight title. He lost by a technical knockout.

According to Thomas Hauser, who wrote an authorized biography of the boxer in 1991 and had access to his medical records, Ali should never have been allowed to enter the ring against Holmes.

Ten weeks before the match, a team of doctors at the Mayo Clinic submitted a medical report to the Nevada State Athletic Commission describing a small hole in his brain's outer layer and noting that the boxer reported a tingling sensation in his hands and slurred speech.

Ali retired permanently in 1981 with a career record of 56 wins -- 37 by knockout -- against five losses.

Ed Schuyler, a boxing columnist for The Associated Press who covered Ali's career, said his boastful statements were not far from the truth.

"He would just work on you -- work on you, work on you -- and he let an opponent know from the day one that he was the man, and the other guy had no shot, and he was lucky that he was even there," Schuyler said.

Parkinson's, and 'a relentless effort to promote peace'

In the years to follow his retirement, Parkinson's disease began to take away Ali's motor skills and his ability to speak coherently, but he never strayed from the spotlight.

"Even though Muhammad has Parkinson's and his speech isn't what it used to be, he can speak to people with his eyes. He can speak to people with his heart, and they connect with him," wife Lonnie Ali said.

She said doctors told her the disease was not the result of absorbing too many punches but a genetic condition.

Ali's fame transcended the boxing ring, and he used that fame toward what his daughter Hana Ali called "a relentless effort to promote peace, tolerance and humanity around the world."

He was welcomed by American presidents and foreign dictators, including Iraq's Saddam Hussein and Cuba's Fidel Castro.

His role as an ambassador of peace started in 1985, Hana Ali said, when he traveled to Lebanon to try to secure the release of four American hostages. In 1990, he was credited with securing the release of more than a dozen American hostages from Iraq just days before the start of the Persian Gulf War and was nominated for the Nobel Peace Prize in 1997.

He also used his fame for charity work, helping raise millions of dollars for food and medical relief around the world. In 1998, he was named a United Nations Messenger of Peace.

"Muhammad feels that everything he did prior to now was to prepare him for where he is now in life," Lonnie Ali said. "He is very much more a spiritual being. He is very aware of his time here on Earth. And he has sort of planned the rest of his life to do things so that he is assured a place in heaven."

One of Ali's last triumphs was the construction of a state-of-the-art museum chronicling his life and promoting peace and tolerance around the world.

His vision became a reality in 2005, when the Muhammad Ali Center opened in his hometown of Louisville, a place he called "the greatest city in the world."

Inside the cultural center and museum, Ali's voice can be heard from plasma screens, reminding those who tried to defeat him that his claim of being "The Greatest" lived up to reality:

"Ali's got a left; Ali's got a right. If he hits you once, you're asleep for the night. And as you lie on the floor, while the man counts 10, hope and pray that you never meet me again."