Onscreen the toughest actors have played historic boxers, but there's nothing like the real thing. In Hollywood's quest for gritty realism, film producers have recruited the fighters themselves. Cassius Clay, Joe Louis and Max Baer have each stepped out of the ring to appear before the camera lens. He was the self-proclaimed "Greatest Boxer of All Time." He also called himself the prettiest fighter to ever enter the boxing ring. He was one of boxing's most controversial figures, and certainly the sport's most colorful--Muhammad Ali. Born Cassius Marcellus Clay Jr. in Louisville, Kentucky, Clay won an Olympic Gold medal in 1960 at the age of 18. Four years later he defeated Sonny Liston for the title of Heavyweight Champion of the World, converted to Islam and changed his name. Ali was full of ego and swaggering style. He was the greatest fighter in the ring, but as the US entered Vietnam, Ali called himself a conscientious objector. He was stripped of his title and forbidden to box. In 1971, the Supreme Court ruled in his favor and Ali returned to the ring, now elevating his sport to an international arena. List of films Today! on TCM Requiem for a Heavyweight (1956) Rocky (1976) Raging Bull (1980) Raging Bull: My Story by Jake La Motta Ali returned to fighting in 1970 in the "Fight of the Century," against Joe Frazier. Their "Thrilla in Manila" has been called the best bout of all time. In 1974, Ali again demonstrated his dexterity against the then-undefeated George Foreman in Zaire to regain the Heavyweight crown. In the athlete's darkest days, Jim Jacobs told the champion's story in AKA Cassius Clay (1970). Jacobs chronicles Ali's rise to prominence and fall to disgrace with archival footage and interviews with the boxer as well as interviews with his opponents and admirers. The Dream Factory brought the biography of Joe Louis to the screen in 1953, but Louis himself had made his own screen debut fifteen years earlier. The year that he avenged himself by cold-cocking his opponent Max Schmeling in the first round, Louis appeared in The Spirit of Youth (1938). With a brilliant all-black cast of seldom-seen performers such as Clarence Muse, Louis stars in the fictional story of a prizefighter who falls for a femme fatale (Edna M. Harris). Louis continued to make guest appearances in film and television throughout the '40s, '50s and '60s. One boxer who seemed to love the close-up even as much as the knockout was Max Baer, who stepped out of the ring and into the spotlight in The Prizefighter and the Lady (1933). Baer plays a boxer who falls for Myrna Loy. In the script, Baer fights Primo Carnera, but his opponent refused to lose on film so the ending had to be rewritten. The following year, Baer and Carnera faced each other for the Heavyweight crown-this time Baer took the title. He was seduced by the glamour of stardom and returned to the screen, notably appearing alongside Humphrey Bogart in The Harder They Fall (1956). Keep your eyes peeled in The Prizefighter and the Lady for some more famous mugs-such as Jack Dempsey.