Vitali Klitschko (born 19 July 1971) and Wladimir Klitschko (born 25 March 1976), collectively known as The Klitschko brothers are Ukrainian heavyweight boxers.

They reside in Germany, where they are media stars. Both brothers made their professional debut on November 6, 1996 in Hamburg. Since then both have been heavyweight world champions in boxing. They have stated they will never fight each other.

After a series of injuries, Vitali had a career break of almost four years. In his comeback fight in Berlin on October 11, 2008 he defeated Samuel Peter to regain the title of WBC world heavyweight champion. At that time Wladimir was already world heavyweight champion with the WBO, IBF and IBO. That was the first time in history with two brothers world champions at the same time. Vitali retained the WBC Heavyweight Championship in 2011. On July 2, 2011, Wladimir won the WBA Title, which means that the Klitschko brothers hold all of the World Heavyweight Titles collectively.

The Klitschko brothers jointly run the professional boxing promotion companies "K2 Promotions" and "K2 East Promotions" , as well as the "Klitschko Brothers Fund", a charity organisation. They appear together on German TV shows and commercials, have a common website klitschko.com and support each other's training and fights.

David Deron Haye (born 13 October 1980) is a British professional boxer from England.

Haye is the former WBA heavyweight champion. He is also the former unified world cruiserweight champion, holding the WBA, WBC, WBO, and The Ring cruiserweight titles, and the former European cruiserweight champion.

Haye started his ambition and passion for boxing at old-school boxing gym Fitzroy Lodge Boxing Club in Lambeth, South London, where he quickly impressed and confidently won his first amateur bouts.

In 1999, 18-year-old Haye participated at the world amateur championships in Houston, Texas, USA at light-heavyweight but was eliminated by experienced American Michael Simms early in the contest.

At the 2001 World Amateur Boxing Championships in Belfast, Northern Ireland he fought in the heavyweight 201 lb division where he beat world class Sebastian Köber to reach the final where he gave Odlanier Solís a standing eight count before being stopped by the Cuban in round three, and taking the silver medal.

Samuel Okon Peter (born September 6, 1980 in Akwa Ibom, Nigeria), nicknamed "The Nigerian Nightmare," is a professional heavyweight boxer and the former WBC heavyweight champion.

Peter rose to prominence as a professional fighter following a string of spectacular knockout wins in his early career, at a time when the division was fragmented. He has won a portion of the heavyweight crown and scored notable wins over: James Toney and Oleg Maskaev. Samuel Peter is also the only man to have been defeated by both Klitschko brothers (losing a total of three bouts against them).

Originally, Peter's preferred sport was soccer. In 1992, some boxers came to Peter's school to train. The curious young 11-year-old stopped by and asked if he could train along with them. He was put up against an experienced amateur and knocked him out. This marked the beginning of a successful amateur career for Peter.

Samuel Peter won the Nigerian amateur heavyweight championship and the Africa Zone 3 Heavyweight championship. He faced stiff competition as an amateur (including a knockout victory over 2000 Silver Medalist Mukhtarkhan Dildabekov of Kazakhstan). However, he prevailed and was given the opportunity to represent Nigeria at the 2000 Sydney, Australia Summer Olympics.