He joined United from Queens Park Rangers in January 2010 and added an extra dimension to Chris Hughton's attack, chipping in with three goals and contributing a handful of assists in the second half of the season to help Newcastle gain promotion back to the top flight.
Routledge was on target at Home Park on the night that Hughton's side memorably clinched the title against Plymouth Argyle and linked up well with the likes of Andy Carroll, Kevin Nolan and Peter Løvenkrands as the Magpies finished up with 102 points, gaining momentum as the season went on.
But while he continued to figure in the Premier League under Hughton the following term, Alan Pardew's arrival saw him rejoin QPR on loan before he signed for Swansea City in August 2011. He spent ten years at the Liberty Stadium, making more than 300 appearances in all competitions, before confirming his retirement on Monday.
Routledge also played for Crystal Palace, Tottenham Hotspur and Aston Villa, as well as spending time on loan with Portsmouth, Fulham and Cardiff, and while he only made 36 appearances for the Magpies, his contribution in black and white was more sizeable than that tally suggests. Everybody at Newcastle United - and particularly the staff who remain from his time on Tyneside - wish him well for the future.