Arsenal have signed Belgium international Leandro Trossard from Brighton for £21m plus add-ons.
He has scored seven goals and provided three assists in 16 top-flight games for Brighton this season, including a hat-trick against Liverpool at Anfield.
Trossard also made three appearances - two as a substitute and one start - for Belgium at the 2022 World Cup.
The Belgian attacker will wear number 19 for the Gunners and manager Mikel Arteta has hailed his quality.
"It is good work from everyone at the club to complete the signing of Leandro," said the Spanish boss.