Arsenal have announced the signing of midfielder Granit Xhaka from Borussia Monchengladbach on a long-term contract.
The Gunners are reported to have paid a fee in the region of £30 million for Switzerland international Xhaka.
Arsenal had been in talks with Gladbach for weeks after Arsene Wenger made Xhaka his top priority this transfer window, and the 23-year-old flew into London on Friday to agree personal terms before joining up with the Switzerland squad ahead of the European Championship.
Pictures of the player wearing the Arsenal shirt had been leaked online in recent days and the club even made light of the fact that the signing was such a poorly kept secret by retweeting fans imploring the club to "announce Xhaka" when confirming the deal.
- Arsenal FC (@Arsenal) May 25, 2016
Arsenal said on their official website that he has passed his medical and that Xhaka's contract will come into effect on July 1, when the transfer window opens.
Wenger said: "Granit Xhaka is an exciting young player, already with good Champions League and Bundesliga experience.
"We have been watching him for a long time now and he is a player who will add quality to our squad. We wish Granit a good Euro 2016 with Switzerland and look forward to welcoming him to Arsenal ahead of next season."
- Gladbach (@borussia_en) May 25, 2016
Gladbach sporting director Max Eberl said: "We're losing a very, very good player, but the agreed transfer fee provides us with the opportunity to make sensible additions to our squad.
"We would like to thank Granit for his hard work and dedication at Gladbach over the last four years and wish him great success at his new club in London."
Xhaka added on the club's official website: "It's a dream come true and I'm happy. I remember I was young and the first game I watched was in the Premier League. I like the style of football. It's aggressive and I like the way Arsenal play football."
Arsenal will hope Xhaka, who was given the captain's armband at Gladbach in September, can add leadership to the Arsenal midfield, with the club losing veterans Mikel Arteta, Tomas Rosicky and Mathieu Flamini this summer.
He is a hard-tackling midfielder who can help shield the back four in a deeper-lying role, but has the creative vision and passing skills that are vital to Arsenal's style of play. He was often at the heart of Gladbach's build-up play, instigating attacks by spraying balls up the field with his left foot.
He played more passes than any other Gladbach player last season (1,883) and also led the team in successful tackles in the Bundesliga, with 54.
He has made more than 100 league appearances for Gladbach since joining from Basel in 2012, while he has 40 caps for Switzerland.
Arsenal only added goalkeeper Petr Cech to the squad last summer, with Mohamed Elneny following in January, but Wenger has said he wants to bring in three players in this window, with a striker now top of the wish list.