Monaco have secured the services of Feyenoord defender Terence Kongolo on a five-year deal.
The Netherlands international only signed fresh terms with the Eredivisie winners in April, but has opted to leave the club whose youth set-up he joined in 2002.
Kongolo made 23 top-flight appearances in Feyenoord's title-winning campaign and is looking forward to helping Leonardo Jardim's Monaco defend their Ligue 1 crown.
"I am very pleased to join AS Monaco," he told the club's official website. "I will discover a new and exciting challenge in a prestigious and ambitious club.
"I look forward to meeting the staff, my new team-mates and doing my best on the field to help the group."
The 23-year-old had been linked with the likes of Everton and Bayer Leverkusen following his impressive displays at De Kuip.
He played for his country at the 2014 World Cup and has two caps to his name.