Born Jozsef Kreul Bugner in Szoreg, Hungary, in 1950, he and his family fled the country after the 1956 Soviet invasion and eventually settled in the United Kingdom.
Bugner began boxing as a teenager and quickly rose through the amateur ranks, winning the ABA light heavyweight title at just 17.
As a professional, Bugner claimed a notable victory over Cooper at Wembley in 1971 to win both the British and Commonwealth heavyweight titles.
His fights against Ali and Frazier further cemented his reputation for toughness.
In their first bout, Ali controlled the fight with superior speed and accuracy, but Bugner went the distance, earning praise for his resilience.
Later that year, he was outpointed by Joe Frazier in a gruelling match after another courageous performance. Bugner lost again on points to Ali in 1975.
Bugner retired a number of times throughout his career. After first hanging up the gloves in 1976, he made several comebacks.
He moved to Australia in the mid-1980s and continued to take on top-level competition, including a defeat by Bruno, who stopped him in the eighth round in 1987.
Bugner retired again but returned nearly eight years later to capture the Australian heavyweight title in 1995.
In 1998, at the age of 48, he won the World Boxing Federation’s version of the heavyweight championship by defeating James ‘Bonecrusher’ Smith, before bowing out of boxing for good in 1999 after a win by disqualification against Levi Billups.
Outside of boxing, Bugner appeared in films including the 1994 action movie Street Fighter and worked as a boxing adviser for the Russell Crowe film Cinderella Man. He was also a contestant on ITV’s ‘I’m a Celebrity’ in 2009.