Karl was born 2 August 1982 in Salisbury, England, is a rugby union player for Harlequins in the Aviva Premiership.
He is a specialist Scrum-half. He is a product of the Bedford Blues academy system, and was promoted to Bedford's Senior team in 2004 and made over 100 appearances for the club until 2009 when he joined Harlequins.
Karl was named in the England Saxons squad on 11 January 2012 but was called up to the Senior England Side for both the 2012 Six Nations and the South Africa tour. He made his England Debut in the second mid-week fixture against South African Barbarians North, replacing his younger brother Lee.
Karl was an integral part to the success of Harlequins winning the 2011/12 Premiership and has now committed himself to the club to 2015.