Jenkins later played for Pontypridd, then for Celtic Warriors before signing for Cardiff Blues. At the Cardiff Blues he won the Amlin Challenge Cup, and reached the Heineken Cup semi final. After an impressive World Cup 2011, his signature was hotly sought after with Bath, Perpignan and Toulon all chasing a deal for the prop. Jenkins joined French Top 14 side Toulon for the 2012-13 season. He became the ninth Welshman to win a Heineken Cup with Toulon when he played as a replacement in the final against Clermont Auvergne. Jenkins is only the second Welsh player to win both European cups, after winning the Amlin Challenge Cup in 2010 with the Cardiff Blues and the Heineken Cup with Toulon in 2013.
International career
Wales
Jenkins made his first appearance for Wales against Romania in 2002. In the 2005 Six Nations Championship he was rated one of the greatest influences in Wales' Grand Slam winning side, scoring a memorable try against Ireland. In November 2007 he was asked to captain Wales against South Africa by Welsh temporary coach Nigel Davies. His reign as captain would last just one game as in December Wales hired Warren Gatland as coach who gave the captaincy to Ryan Jones. However Jenkins kept his place in the squad solidifying himself as number one choice for the #1 jersey. Jenkins captained Wales against Australia on 28 November 2009 following the withdrawal of regular captain Ryan Jones from the squad due to injury. He captained Wales in their last game of the 2013 six nations championship in Cardiff. Wales defeated England 30-3 to win the Championship. On 30 November 2013 versus Australia Jenkins became the most capped forward for Wales, surpassing Martyn Williams record of 100 caps. On 15 March 2014 versus Scotland he became the most capped player for Wales, overtaking the record of 104 caps held by Stephen Jones. Jenkins became the world's most capped prop forward ever on 29 August 2015 versus Ireland, overtaking the record of 119 caps held by Jason Leonard. Gethin Jenkins took part in both the 2016 Six Nations and the Wales tour to New Zealand. Jenkins also captained Wales during the 2016 Autumn internationals.
British and Irish Lions
He was selected for the British and Irish Lions tour to New Zealand in 2005 and played in all three tests. On 21 April 2009, Jenkins was named as a member of the British and Irish Lions for the 2009 tour to South Africa. In June 2009 Jenkins, Adam Jones and Matthew Rees were selected as the British and Irish Lions front row for the second Test against South Africa. This was the first time an all-Welsh front row was selected for a Lions test match since Billy Williams, Bryn Meredith and Courtney Meredith on the 1955 Lions tour. He was selected for the British and Irish Lions for the 2013 tour for the third time, but withdrew due to injury.
Jenkins has also played rugby league, making regular appearances for Cardiff Demons in the late 1990s leading them to the 1998 Division Two Academy Grand Final.
