[12] His paternal grandparents settled in Britain after the Second World War, during which his grandfather Giuseppe had served in the 12th Infantry Division Sassari, but had returned to live in Italy by the end of the 1950s.

Calzaghe's father worked several jobs as a teenager in Italy, including as a barman, a chef, and a cleaner, before travelling Europe as a busker.

[13] Calzaghe was born in Hammersmith Hospital in March 1972,[13] before his father decided to move the family back to Sardinia at the end of the year, living in his grandfather's home in Bancali.

However, his mother again pushed to return to Britain and the family lived with his maternal grandmother in Markham for three years before they moved into their own home on a council estate in Pentwynmawr, near the town of Newbridge, in Caerphilly County Borough, South Wales.

He attended the local school, Pentwynmawr Primary, along with his two sisters, Melissa and Sonia, and developed a keen interest in playing football.

[14] At the age of eight, he was given a children's boxing toy that developed his interest in the sport and his father made a punching bag from an old carpet.

Calzaghe received his last two defeats in a boxing ring at the hands of Michael Smyth in the 1990 Welsh ABA Final, and against Romanian amateur Adrian Preda at the 1990 European Junior Championships in Prague.

[21][22] In September 1993 Calzaghe was signed up and made his professional debut at Cardiff Arms Park on the Lennox Lewis vs. Frank Bruno bill the following month, halting 23 fight veteran Paul Hanlon in one round.

By September 1995, Calzaghe had won thirteen out of thirteen fights, including seven in the first round and two in the second, including quickfire victories over the highly experienced American duo of Frank Minton and Robert Curry, with only the fully fledged British Light Heavyweight Bobbie Joe Edwards lasting the distance.

In October 1995, Calzaghe won the vacant British super-middleweight title, stopping the previously unbeaten Stephen Wilson in the eighth round.

"[23] After beginning 1996 with two more quick knockouts over Guy Stanford and Anthony Brooks, he successfully defended his British title with an easier-than-expected fifth round stoppage of the tough undefeated puncher Mark Delaney (21–0).

Warren, who had managed Nigel Benn for his first twenty fights, declared: "Joe Calzaghe is a far better prospect, in fact he is my fighter for the new millennium.

"[24] Calzaghe continued his winning ways in 1997, defeating Carlos Christie, the unbeaten Tyler Hughes and the 45–2 Luciano Torres.

After Collins retired, a fight against British boxing legend Chris Eubank was quickly set up for the vacant WBO title on 11 October 1997, in Sheffield.

Calzaghe emerged victorious over the two-time WBO champion, knocking the granite chinned Eubank down in the opening seconds and claiming a unanimous points win.

[25] His popularity grew alongside the wider cultural movement of Cool Cymru, and Calzaghe was symbolic of the new Welsh identity which was forming.

Calzaghe then went on to defeat perennial contender Juan Carlos Gimenez Ferreyra (TKO after 9 rounds), a former opponent of both Nigel Benn and Chris Eubank.

[28] Calzaghe finished the year with another points win against Australian Rick Thornberry, where he broke his hand in the third round after looking like overwhelming his opponent early.

2000 started with another points decision against fellow Briton David Starie, in what was a dull fight that had a lot of holding and with the boxers' respective styles never gelling.

[30] 2002 started with unanimous points wins against former IBF world champion Charles Brewer of the United States in Cardiff, followed by a shutout 12-round unanimous decision over Miguel Angel Jimenez (120–107 for Calzaghe on all three judges' scorecards), and then a quick second round TKO of American Tocker Pudwill,[31] who took the fight at very short notice as a replacement for the injured Thomas Tate, in Newcastle in December.

"[33] Calzaghe's only fight of 2003 was in June against another former world champion, in the shape of American Byron Mitchell at the Cardiff International Arena.

[35] 2004 started out with a defence against Armenian contender Mger Mkrtchian in Cardiff where he won easily by a seventh-round knockout, followed by a points win over Egyptian-American Kabary Salem in Edinburgh in October, during which Calzaghe was briefly knocked down in the fourth round by a right hand.

On 10 September 2005, Calzaghe fought the Kenya boxer Evans Ashira and won by a comfortable unanimous decision over the former Middleweight title challenger, despite breaking his left hand in the third round.

His scheduled unification bout with IBF super-middleweight champion Jeff Lacy for 4 November 2005 was initially canceled due to the break sustained to the metacarpal in his left hand.

Warren successfully rescheduled it for 5 March 2006, and the match was won by an easy unanimous points decision over Lacy, who was a pre-fight favourite with the bookmakers[40] and American pundits alike.

[42] Two points were deducted from Bika for head butts, one of which led to a severe cut over Calzaghe's left eye[43] which would cause him problems for the duration of the bout.

On 27 November 2006, it was announced that Calzaghe had signed a contract to defend his WBO super-middleweight title against former star of The Contender Peter Manfredo Jr. of the United States on 7 April 2007, at Millennium Stadium in Cardiff, Wales, to be shown on HBO.

In May 2007, Frank Warren released details to BBC 5 Live and on his website that Calzaghe had accepted Mogens Palle's offer of $5 million to fight undefeated WBA & WBC world champion Mikkel Kessler.

Calzaghe won by unanimous decision, surpassing the 20 defences made by Bernard Hopkins and Larry Holmes at middleweight and heavyweight respectively.

On 19 April 2008, at the Thomas & Mack Center in Las Vegas,[58] Calzaghe defeated Bernard Hopkins to win The Ring Light Heavyweight Championship by a split decision in his first ever fight in the United States.