German forward Lukas Podolski is leaving Cologne this summer to join Arsenal.
The 26-year-old will add to an Arsenal front line that has been reliant on Robin van Persie.
''The transfer gives me the possibility to play at international level in a top European club,'' Podolski told Cologne's website.
Podolski's contract at Cologne, which could still be relegated from the Bundesliga with one match remaining, was due to expire in a year. Arsenal said Podolski had agreed a ''long-term'' contract.
''We are happy to have made this signing early and we are looking forward to watching Lukas contribute at the European Championship over the summer, a level where he has already made 95 caps at the age of 26,'' Arsenal manager Arsene Wenger said. ''That is a phenomenal record and just shows his quality as a player.''
With two matches left in the Premier League, Arsenal is third and on track to join Manchester United and City in the Champions League.
The Polish-born forward left Cologne once before, spending three mostly unsuccessful seasons at Bayern Munich before returning in 2009 to the club he joined when he was 10.
''I'll carry Cologne always in my heart and we have to pull all our forces together now and concentrate solely on avoiding relegation,'' Podolski said.
Podolski has 18 goals this season and 43 for Germany.
His signing will bolster an attacking unit at Arsenal that already includes Van Persie, Theo Walcott, Gervinho, Alex Oxlade-Chamberlain and Marouane Chamakh.
Van Persie has scored 28 goals in the league this season, earning him the player of the season award in England.
