Arsène Wenger started his Arsenal managerial career back in 1996 and during his time as Gunners boss, they've won three Premier League titles, five FA Cups and appeared in the the UEFA Champions League final back in 2006.
It was also during his reign Arsenal moved to a their newly built stadium the `Emirates` in August 2006, after spending 93 years at Highbury.
Although Wenger's transfer policy has been called into question in recent years, he remains one of the best managers around, becoming the Gunners longest-serving manager and the most successful in terms of major trophies won.
However, Arsenal chief executive Ivan Gazidis has admitted that replacing the Frenchman will be a great challenge.
“So much of the attention on a football club is around an individual and that’s very understandable at Arsenal because we have a giant who’s managing us,” Gazidis told Arsenal's official website.
“Arsene has been a fantastic driver and has put the club in a great, great position.
“The biggest challenge we're going to face as a club is that, when the transition from Arsene to the next manager of our football club happens – and I don't know what that’s going to be – that we come through that strongly.”
Gazidis also commented on the Gunners winning the FA Cup back in May, which saw the North London side end their nine-year trophy drought.
He added: “Winning the FA Cup was a fantastic moment.
“In my life, that’s one of my greatest moments. The moment you get away from the euphoria of the moment, the next question is, ‘How do we have more of that?’
“We want this football club to be at the top of the world’s game. If the manager believes in someone like Mesut Ozil, he can buy him. It’s the same with Alexis Sanchez.
“Underneath that tip of the iceberg, those star signings that we talk a lot about, there’s an awful lot else going on. Our youth development, for example, is going to be the foundation of this football club going forward.
“Where we are currently is off the shoulder of the world’s top teams. I don't think we're at that level yet, but that’s where we're aiming to get to. We want Arsenal to be in that elite group of football clubs around the world.”