Arsenal made the announcement on this morning (Friday) and, according to sources, Wenger had already informed the squad of his decision during training before their home match against West Ham on Sunday.

The Frenchman had signed a two-year contract extension last summer and, while there was intense speculation that Wenger would leave midway though his contract, the sudden announcement came as a surprise, given that it was midseason and that Arsenal face a Europa League semi-final against Atlético Madrid.

Wenger's statement, posted on Arsenal's website, reads: “After careful consideration and following discussions with the club, I feel it is the right time for me to step down at the end of the season. I am grateful for having had the privilege to serve the club for so many memorable years.

“I managed the club with full commitment and integrity. I want to thank the staff, the players, the directors and the fans who make this club so special. I urge our fans to stand behind the team to finish on a high. To all the Arsenal lovers take care of the values of the club. My love and support for ever.”

Wenger's long career has been seen by many to be a game of two halves (sorry). His early years saw him inject fresh new techniques into the game, as well as exemplifying his keen eye for young, overseas talent. The club won three Premier League titles between 1997-2004, and even reached the Champion's League final in 2006.

But following on from this, Wenger's - and Arsenal's - problems became frustrating for the fans. Financial restrictions, player losses and and embarrassing defeats meant that Wenger's previous reputation was apparently the only thing allowing him to stay on at the club - even as it was gradually eroding year on year.

Despite this, he'll still be seen as a seismic figure in the sport and one of the most dynamic managers in modern football history.