Matt O’Riley has joined Brighton from Celtic on a five-year contract.
The 23-year-old Denmark midfielder joins Albion for a reported £25million, subject to international clearance.
O’Riley featured more than 100 times for the Hoops over two-and-a-half years, scoring 27 goals and helping Celtic win the Scottish Premiership on three occasions.
Brighton boss Fabian Hurzeler said: “He plays a very specialist position. He is very good at occupying and attacking the right space and likes making deep runs, knowing when to attack at the right time.
“He enjoys getting forward and attacking the opponent’s penalty area, but he also has a good defensive instinct. That balance makes him special.
“He is a great character, and has a good ambition to succeed and that’s something which is very important for us.”
The likes of Atletico Madrid and Atalanta failed with bids for O’Riley this year and he looked destined to move on this summer, but he admitted that leaving Celtic was not an easy task.
“People probably don’t realise how big the club is until you get up there. It’s a real family club and one that I was made to feel welcome at very early on.
“It’s a very unique place just in terms of the passion the fans had, (it) is something I had never experienced before. I thoroughly enjoyed my time there.
“Celtic made me mature a lot as a person. You need to win every single game. If you don’t win every single game, even if it’s against strong opposition like Rangers, then it’s an absolute disaster.
“So you really have to be on it and that relentless winning mentality has set me up for the next challenge. I hope I can bring some of that.”