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Takes up boxing, wins his first bout -

Born Cassius Marcellus Clay Jr. on January 17, 1942 in Louisville, Kentucky, he began training as a amateur boxer in 1954, aged 12, after his bike was stolen. The distraught youngster reported the theft to policeman and boxing enthusiast Joe E. Martin, who suggested he take up the sport and invited him to come around to his gym. It was there that Martin taught him to box. Six weeks later, the young athlete won his first bout.

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Gold at the Rome Olympics -

In 1960, he won boxing gold at the Olympic Games in Rome, beating Poland's Zbigniew Pietrzykowski. He's seen standing tall on the winners' podium with Pietrzykowski, Italy's Giulio Saraudi and Anthony Madigan from Australia.

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Self-confidence, self-promotion -

The boxer won a string of bouts after correctly predicting the round in which he'd floor his opponent. It was an early example of his burgeoning self-confidence. But occasionally, he would miss the mark. In February 1962, he stopped Don Warner (pictured) in four rounds, rather than the five forecast. He later said he deliberately brought his victory forward by one round because Warner had failed to shake hands. The boxer from Louisville was sharpening his promotional skills too!

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Out in five -

In this image, the boxer predicts knocking out Britain's Henry Cooper in five rounds after arriving in London in May 1963. He ultimately did get him in the fifth.

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The Ring magazine -

The boxer on the cover of the September 1963 edition of The Ring magazine. He was named "Fighter of the Year" by the publication more times than any other fighter.

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Beating the Beatles -

In 1964, he earned himself a fight with heavyweight champion Sonny Liston. While the boxer was training at the 5th Street Gym in Miami, he was visited by four young lads from Liverpool: John, Paul, George, and Ringo.

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Winning the world heavyweight title -

In 1964, he "shook up the world" by dethroning Sonny Liston to take the title. The boxer predicted victory, boasting that he would "float like a butterfly, sting like a bee" and knock out Liston in the eighth round. In fact, he forced his opponent to quit in the sixth round. It's after this fight that the new champ declared to reporters that he was the "greatest."

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Cassius Clay becomes Muhammad Ali -

Shortly after the Liston upset, the boxer announced that he no longer would be known as Cassius Clay, but as Muhammad Ali. He converted to Islam and affiliated himself with the Nation of Islam. His decision to do so ranks among the most defining moments of his extraordinary life. He is seen here as the Nation of Islam's Malcolm X takes his photograph.

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Liston rematch -

Sonny Liston attempted to regain his crown on May 25, 1965, but was floored by Ali in the first round of their rematch. Debate still rages around whether Liston, who was connected to the mob, took a dive. Ali was furious and taunted Liston to get up (pictured). In January 1971, Sonny Liston was found dead in his Las Vegas home, apparently from a heroin overdose. But his death remains a mystery, and suggestions still linger that the disgraced former champ was murdered.

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Liston rematch -

Sonny Liston attempted to regain his crown on May 25, 1965, but was floored by Ali in the first round of their rematch. Debate still rages around whether Liston, who was connected to the mob, took a dive. Ali was furious and taunted Liston to get up. In January 1971, Sonny Liston was found dead in his Las Vegas home, apparently from a heroin overdose. But his death remains a mystery, and suggestions still linger that the disgraced former champ was murdered.

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Vietnam War and resistance to the draft -

In 1966, when Muhammad Ali realized that he was eligible for the draft, he was asked by reporters where he stood on the Vietnam War. He declared angrily: "Man, I ain't got no quarrel with them Vietcong." He was immediately accused of being a draft dodger.

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Taking the belt out on the road -

Meanwhile, Ali continued to fight. But with US audiences increasingly hostile towards his stance on the conflict in Southeast Asia, he took his belt on the road. He defended his title in Canada against George Chuvalo and also fought in Europe. But things were starting to get ugly back home.

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Stripped of license -

On April 28, 1967, Ali refused his induction into the US Army. Later the same day, the New York State Athletic Commission suspended his boxing license and stripped him of his title.

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Banned from boxing -

Ali was against the ropes. His outspoken political views and his very public opposition to the Vietnam War polarized America. The impact of Ali's draft refusal was profound. Despite being ostracized by many (at the time there was still widespread support for the war), Ali's example inspired many black Americans and others. In fact, civil rights figures came to believe that Ali had an energizing effect on the freedom movement as a whole.

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"Fight of the Century" -

After four years in the boxing wilderness, Ali's license to fight was reinstated. He met new heavyweight champion Joe Frazier at Madison Square Garden in New York on March 8, 1971 for what was billed as the "Fight of the Century." But Ali lacked his edge and was defeated. Frazier became the undisputed heavyweight champ of the world by winning a unanimous 15-round decision.

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"Rumble in the Jungle" -

Joe Frazier was later defeated by George Foreman, opening up the way for the legendary "Rumble in the Jungle" between Foreman and Ali. Held on October 30, 1974 in Kinshasa, Zaire (now Democratic Republic of the Congo), the pair slugged it until the eighth, when Ali pounded the champ to the floor to win back the title.

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"Rumble in the Jungle" -

Joe Frazier was later defeated by George Foreman, opening up the way for the legendary "Rumble in the Jungle" between Foreman and Ali. Held on October 30, 1974 in Kinshasa, Zaire (now Democratic Republic of the Congo), the pair slugged it until the eighth, when Ali pounded the champ to the floor to win back the title.

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"Thriller in Manilla" -

The following year, Ali met Joe Frazier in the grueling "Thriller in Manila," an epic bout in which the defending champion survived 14 brutal rounds with Frazier before claiming victory by a technical knockout. It was a defining win for Ali and further cemented his boxing legacy.

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The "Ali Shuffle" -

Out of the ring, Muhammad Ali served as an in-demand public speaker. He's seen here during an engagement with graduating seniors at Harvard Business School in 1975 and demonstrating the famous "Ali Shuffle." Ali was renowned for his fancy footwork, and the shuffle was first unveiled back in 1966 during a fight with Cleveland "Big Cat" Williams.

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East meets West -

Less publicized is Muhammad Ali's extraordinary 1976 wrestling-boxing bout with Japanese wrestler Antonio Inoki. Ali and Inoki fought 15 rounds, with the match ending in a draw.

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'The Greatest' (1977) -

Ali portrayed himself in this biographical sports drama based on the book 'The Greatest: My Own Story.' Ernest Borgnine played Ali's trainer, Angelo Dundee.

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Three-time heavyweight champion -

Now 36 years old, many expected Ali to retire. But he climbed back in the ring in February 1978 for a clash with Leon Spinks, which he promptly lost. Later the same year, on September 15, the two met again. This time Ali regained the WBA heavyweight title and avenged his split decision loss to Spinks from seven months prior. Afterwards, Ali promised he would retire.

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Battered and bruised -

But Ali couldn't stay away, and in 1980 made the disastrous decision to meet Larry Holmes, his former sparring partner and the new champion, in Las Vegas. The bout took place on October 2 and ended in ignominious defeat for a tired and drained Ali. Many commentators believed the fight should never have gone ahead and suggested the punishment Ali received on the night further contributed towards his declining health. Ali is pictured the day after the fight at a press conference wearing dark sunglasses and a swollen face.

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Lighting the Olympic flame -

Muhammad Ali retired from boxing in 1981. In 1984, he made public his diagnosis of Parkinson's syndrome and largely stepped back from personal appearances. He made center stage, however, in 1996, when he was invited to light the Olympic flame during the Opening Ceremony of the XXVI Summer Olympic Games on July 19 in Atlanta, Georgia.

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World Sports Awards of the Century -

As his career was being reappraised, Ali was honored with several awards and citations. He's pictured in November 1999 receiving the World Sports Awards of the Century for the martial arts category during the World Sports Awards ceremony at the Vienna State Opera.

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Celebrity status -

Back on his feet and back in the  headlines, Ali was feted by a host of celebrities as he attended award ceremonies across the United States. Here he is with fellow hitmaker Eric Clapton during the 1999 VH1-Concert of the Century at The White House in Washington, D.C.

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Sports Personality of the Century -

In 1999, a one-off award voted for by the British public selected a Sports Personality of the Century. The honor went to Ali.

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Presidential Citizens Medal -

Meanwhile, Ali was becoming a familiar figure at the White House. In 2001 US President Bill Clinton presented the boxing legend with the Presidential Citizens Medal.

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'Ali' (2001) -

The biographical sports drama film 'Ali' was released in 2001. Well received by critics, the movie garnered a Best Actor Oscar nomination for Will Smith for his portrayal of Ali.

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Medal of Freedom -

The former boxer was back in Washington, D.C. in 2005 to receive the Medal of Freedom from US President George W. Bush.

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Otto Hahn Peace Medal -

In 2005, Ali was honored with the prestigious Otto Hahn Peace Medal. The citation reads: "For outstanding services to peace and international understanding, especially for his lifelong commitment to the American civil rights movement and the cultural and spiritual emancipation of black people throughout the world." Ali is pictured with his wife Lonnie Ali and Christine Kalb, chairwoman of the German Society For The United Nations. 

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Muhammad Ali Center -

Also in 2005, the Muhammad Ali Center was inaugurated. The building serves as a museum and multicultural center dedicated to the former boxer. It's located in downtown Louisville, Ali's hometown.

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Tribute on Hollywood Walk of Fame -

Shortly after Muhammad Ali's death on June 3, 2016, a makeshift memorial for the boxing great appeared near Ali's star on the Hollywood Walk of Fame. His is the only star to stand upright. Asked why that was, Ana Martinez, the producer of the Walk of Fame ceremonies, said Ali "did not want the name of Muhammad to be stepped on."

Sources: (Boxing News Online) (History) (Time) (World Boxing News) (National Geographic) (The Guardian) (Boxing Social) (USA Today)

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