Swedish tennis champion Bjorn Borg and 8-year old American tennis player Andre Agassi photographed at Caesars Palace Resort Casino in Las Vegas in 1978.  

Shaquille O’Neal is photographed at his home in Los Angeles, California on September 7, 1993. Pictured then at age 21 and a member of the Orlando Magic, Shaq is now regarded as one of the greatest basketball players and centers of all time.

Joe Namath of the New York Jets is shown in uniform during a photoshoot at Life Studios in New York City on July 23, 1966. The shoot of the famous quarterback would go on to be featured on Sports Illustrated's October 1966 cover.

Diego Maradona training with the national team April 12, 1982 in Bueno Aires 

The Argentine football team play the USSR during the Falklands War, Buenos Aires, Argentina, 1982. Among the team is Diego Maradona.  

George Best of Manchester United escapes a tackle from Crystal Palaces' David Payne during a match on February 14, 1970. The game between the two first division teams was held at Old Trafford stadium in Manchester and resulted in a 1:1 tie.  

George Foreman lands for a portrait session in St Lucia in March of 1991. Nicknamed "Big George" the former professional boxer won two heavyweight championships and an Olympic gold medal before becoming an entrepreneur.

Mike Tyson photographed whilst training in Catskill, New York on November 28, 1985. The American former heavyweight boxer nicknamed "Iron Mike" and "Kid Dynamite" is notorious for having bit off rival Evan Holyfielder's ear during a 1997 match.

Football legend Pele poses with the World Cup Trophy on the beach near his home in Santos, Brazil in April of 2013. It was this opportunity to photograph Pelé that brought O'Neill briefly out of retirement. 

They Must Fall: Muhammad Ali and the Men He Fought features powerful and often moving images and stories of Muhammad Ali and the men he challenged in the ring, by award-winning photographer Michael Brennan. Brennan spent decades locating Ali’s former opponents to discover what had become of them. Alongside the photos and stories of fighters such as George Foreman, Joe Frazier, Buster Mathis, Leon Spinks, and ‘Sweet Jimmy’ Robinson, this unique book is also a look through Brennan’s remarkable Ali archive, including time spent with great fighters at the Deer Lake training camp, press conferences and in the ring. This special edition, limited to only 50 copies, contains numerous never-before-seen photos plus poignant stories illuminating the images and contextualizing Ali’s powerful role in the world of sport.

A battered Sylvester Stallone is photographed on set as Rocky Balboa during the filming of the boxing movie Rocky II in Los Angeles in November of 1978. The Rocky series follows the underdog boxer who fights numerous brutal opponents and wins the world heavyweight championship twice. 

Muhammad Ali is photographed practicing his form in the mirror at his training camp in Deer Lake, Pennsylvania in 1977. Nicknamed "The Greatest", Ali is widely regarded as one of the most significant and celebrated sports figures of the 20th century and is frequently ranked as the greatest heavyweight boxer of all time.