West Ham have announced the appointment of Slaven Bilic as their new manager on a three-year contract, subject to receiving a work permit.
Bilic left Besiktas this summer after leading the Turkish club to third-place finishes in both his seasons in charge.
The Croatian, who played for West Ham for 18 months in 1996 and 1997, succeeds Sam Allardyce, who left Upton Park at the end of the season when his contract was not renewed.
We are delighted to announce the appointment of Slaven Bilic as the Club's new manager http://t.co/Ejx8qvIq1B #whufc pic.twitter.com/w1ynoq3QcP
- West Ham United FC (@whufc_official) June 9, 2015
Bilic told the club's official website: "I'm really glad to be back with West Ham United. It's in the Premier League, which is among the best in the world. It's a big challenge and you are competing with the best and what better club to do it with than West Ham.
"I remember West Ham as a special club. I love these kinds of special clubs. My last club, Besiktas, was that kind of club. It's not about the size -- West Ham is big club -- there is something special about them: they are a cult clubs.
"It is a great place to play and I felt like I was at home. It is a big privilege and a big responsibility to now be manager and I hope that I will prove it to the board, players and fans.
"My first priority when choosing a club is to look at its ambitions. When I spoke to the chairmen and Karren Brady, they made clear that it is not only the fantastic new stadium we are moving into, but they showed their determination and ambition to make what is a big club even bigger.
"I saw their determination and passion that they want to do that. That was the number one reason. I could feel that they really wanted me so it was an easy choice.
"I would say to the West Ham fans that I will give my best and together we will achieve great things."
David Sullivan, the club's joint-chairman, said West Ham should be aiming for a top-eight finish and a strong cup performance in the new season, as stage one of "a three-year project".
He added on the club's website: "It is very good for the club and the supporters. We have taken a man who understands the West Ham Way. It is important how we play and that the players play with passion.
"I think he will bring a few of the West Ham legends to be part of his entourage and I think that is very good because it strengthens the bond with the supporters. He will take us into the Olympic Stadium and I think he will be here for a long time.
"We have appointed a manager that we know the supporters wanted."
Marseille boss Marcelo Bielsa was also reported to be a serious contender for the position.
West Ham co-chairman David Gold indicated the club were determined to "bring in an established manager who has been there and done it" on Monday as they prepare to move into the Olympic Stadium from the 2016-17 season.
Bilic, 46, has coached at international level with Croatia and also in Europe with Besiktas as well as at Lokomotiv Moscow.