The death of boxing legend Muhammad Ali last night (June 3) at the age of 74 has brought out tributes from around the globe on social media. You can read what rockers like Paul McCartney, Sammy Hagar and Slash have said in his memory.

Born in Louisville, KY, as Cassius Clay, he became world heavyweight champion on Feb. 25, 1964, when Sonny Liston failed to answer the bell for the seventh round. Shortly thereafter he announced that he was converting to Islam and changed his name to Muhammad Ali. As much as he was celebrated for his charisma and dazzling skill in the ring, he was a lightning rod of controversy. His boasting that he was "The Greatest" and taunting his opponents came at a time when athletes -- particularly African American ones -- were expected to behave a certain way. And his political activism, speaking out for civil rights and against the Vietnam War, earned him many detractors.

In 1967, his refusal to be inducted into the armed services due to his antiwar stance nearly cost him his career. He was stripped of his title, his boxing license was revoked in all 50 states and he was convicted of draft evasion. He was allowed to resume his career in 1970, when his licenses began to be re-instated, and the Supreme Court unanimously overturned the conviction a year later.

He regained the title in 1974, after the famous "Rumble in the Jungle" with George Foreman, and held onto it for three-and-a-half years, when Leon Spinks won a split decision in February 1978. Although he won it back from Spinks seven months later, by then, he was nearly 37 and a shell of his former self. He retired three years later after his next two fights ended in losses, bringing his career record to 56-5 (37 by knockout).

Ali was diagnosed with Parkinson's disease in 1984, which many experts believe happened as a result of the beatings he took in the ring. But he remained an in-demand celebrity and in the last few decades of his life, the controversies were well in the past and he was universally beloved for his talent, warmth, brilliance, humanitarian efforts and, most of all, courage. His lighting of the Olympic torch in 1996 -- maintaining his dignity as his body shook uncontrollably -- remains the ultimate expression of the Olympian ideal of triumphing over adversity.

Of the rockers whose lives he touched, McCartney put it best in a full statement on his website. "Dear Muhammad Ali," he wrote. "I loved that man. He was great from the first day we met him in Miami, and on the numerous occasions when I ran into him over the years. Besides being the greatest boxer, he was a beautiful, gentle man with a great sense of humour who would often pull a pack of cards out of his pocket, no matter how posh the occasion, and do a card trick for you. The world has lost a truly great man. Love Paul."

Read below to see what others are saying about him.

Rockers We've Lost in 2016