Wladimir Klitschko confirmed his retirement from boxing on Thursday, ending an illustrious career comprising 69 professional fights and a remarkable 23 world title defences.

We take a look back at the Ukrainian's six most significant bouts, including the epic contest with Anthony Joshua that proved to be his last fight.

October 2000 - Byrd bossed for title #1

Klitschko claimed his first world title in October 2000, defeating the man who had seized the WBO belt from his brother, Vitali.

Chris Byrd was fortunate in the extreme to claim victory over Vitali. After stepping in to face the then-undefeated world champion as a late replacement for Donovan Ruddock, Byrd was well down on all three scorecards when Klitschko suffered a serious shoulder injury that rendered him unable to continue after the ninth round.

Six months later, Wladimir won a lopsided, unanimous decision to ensure the WBO title returned to the Klitschko family, knocking Byrd down twice in the latter stages.

March 2003 - A low point, but also a turning point

After five successful defences, Klitschko lost his WBO belt in humiliating fashion when he was stopped by South Africa's Corrie Sanders just 27 seconds into the second round of their contest.

While the defeat was a troubling one, it also served as a notable turning point in his career. Before long, Klitschko had the great Emanuel Steward in his corner and their alliance would prove a hugely prosperous one.

Steward had not been with Klitschko for long when the latter suffered another loss, at the hands of Lamon Brewster, in April 2004. He was not beaten again until November 2015.

September 2005 - I get knocked down, but I get up again

Significant doubts over Klitschko's chin remained when he was sent to the canvas on three occasions by Samuel Peter in September 2005. However, no one could doubt the spirit and resilience shown by Klitschko as he nevertheless bounced back to win a dramatic final eliminator.

"I have put my losses behind me," said the victor. "It's wonderful to be back in the heavyweight picture."

Klitschko's victory earned him another meeting with Byrd, in which he secured the IBF belt he would go on to hold for more than nine years.

July 2, 2011 - Klitschko silences his doubters and Haye

While Klitschko continued to chalk up successful defence after successful defence in the years that followed his second triumph over Byrd, he often faced criticism over the calibre of his opponents.

A high-profile unification fight with David Haye gave Klitschko a chance to silence his doubters ... and he was able to do just that.

Despite a host of confident pre-fight pronouncements, Haye was comprehensively outboxed by his experienced rival - the Briton later citing a broken toe as a significant factor in his underwhelming display.

October 5, 2013 - Another pretender to the throne dismissed

Like Haye before him, Alexander Povetkin was expected to provide a stiff challenge for the ageing Klitschko.

However, the Russian also found himself soundly beaten as Klitschko registered victory by a wide margin in Moscow. 

The fight was certainly not a classic - as the champion clinched repeatedly to sap his opponent's energy - but represented another significant milestone in Klitschko's career, which would feature three further victories over Alex Leapai, Kubrat Pulev and Bryant Jennings before Tyson Fury brought the Ukrainian's lengthy winning streak to an end.

April 29, 2017 - A champion in defeat

Seventeen months on from his shock defeat to Fury, Klitschko was beaten again in his final fight against Anthony Joshua, but undoubtedly enhanced his reputation in the process.

Now 41, Klitschko put in a superb, courageous performance that belied his advancing years, recovering from a fifth-round knockdown to sensationally put the heavyweight division's new star attraction on his back in the sixth.

A dramatic contest remained in the balance before the veteran was finally stopped in round 11.

Fully deserving of the praise that came his way in the aftermath of the fight, Klitschko could hardly have done more in defeat.