Byrne has built a reputation as one of the best fullbacks in the game since cementing his place within the Wales side at the beginning of 2008.

Following a cruciate knee injury in 2004, Byrne made his senior debut as a replacement against New Zealand in 2005 and he was a regular starter during the 2006 Six Nations and toured Argentina in the summer, scoring his first try in the second Test against the Pumas.

He received a Wales squad call-up for the 2006 autumn internationals and appeared against the Pacific Islands and scored a try in the 38-20 victory.

Injury would hamper his career again with just one appearance in the 2007 Six Nations after recovering from a knee injury. He later received a call-up for Wales's two-Test tour to Australia in May that year and made the starting line-up for the first Test loss in Sydney. Byrne was subsequently named in coach Gareth Jenkins's 41-man preliminary Rugby World Cup 2007 summer training squad but failed to make the final cut.

In November 2007, Byrne was selected in Wales caretaker coach Nigel Davies's 31 man squad ahead of the Prince William Cup clash with South Africa. He made the starting line-up but had to withdraw from the team due to an injury picked up while on Regional duty with the Ospreys.

In January the following year Byrne was included in Warren Gatland's 28-man squad for the Six Nations, and played in every game of the Grand Slam-winning campaign. The fullback enjoyed a hugely successful season, winning many plaudits for his superb form and scoring three tries to boot; one against England in the victory at Twickenham and a brace against Italy in his man of the match performance.

He followed this up with three more eye-catching displays in that year's November internationals agaist South Africa, New Zealand and Australia - scoring a try in the victory over the Wallabies - and remained a core member of the squad for the 2009 Six Nations.

He was subsequently selected to tour South Africa with the elite tourists and won a Lions cap in the first Test in Durban but was troubled by a long-standing foot injury during the tour. However, it was a thumb injury that curtailed his tour prematurely.

A Welsh Schools cap, Byrne began his career at Bridgend Athletic and later played for Tondu RFC, Bridgend, Llanelli and the Scarlets. He joined the Ospreys in 2006 and won the inaugural Magners League Grand Final with the region before agreeing a move to French side Clermont Auvergne in January 2011.