Arsenal have confirmed the signing of midfielder Thomas Eisfeld from Borussia Dortmund.
Eisfeld, 19, has committed to a long-term contract at Emirates Stadium after impressing for Dortmund's Under-19 team.
"I feel very proud to have signed for Arsenal," he told the club's official website. "This is a great club, with many great players, and I'm so happy to be joining Arsenal.
"It's a real honour to be team-mates with the great players at Arsenal, and also training everyday with players like Tomas Rosicky - who I grew up watching play at Dortmund. I will give it everything I have here and do my best to make the manager, players and fans happy.
"I would also like to thank Borussia Dortmund, where I played for the last seven years, for everything they have done for me. I had a great time there, and there were many wonderful coaches who helped me get to where I am today."
Arsene Wenger added: "Thomas is a player we have liked for some time. We've watched him closely this season, where he has excelled for Dortmund's youth team.
"He is young but has proven to us that he can play, that he has the attitude and technical ability to be a valuable addition to our squad. We're very pleased to welcome him to the club and look forward to his contribution in the coming seasons."
The fee is reported to be in the region of £400,000.