Tottenham have completed the signing of Southampton's teenage Welsh international defender Gareth Bale.
Bale has one year left on his deal at Southampton
Southampton said Spurs will make an immediate payment of £5m, with further additional payments that could see the transfer fee rise to £10m.
The 17-year-old Bale said: "I'm just excited to be coming to a massive club like Spurs. It's pushing forward and I want to be part of its future."
Bale had only one year left on his Southampton contract.
The youngster had also been linked with moves to Arsenal and Manchester United.
Spurs had a bid of about £10m accepted by Saints in January, but Bale rejected the transfer at that time.
Following Southampton's failure to gain promotion this season the prospect of first-team football in the Premiership at Tottenham looks to have been enough to change his mind.
"I really want to play in the Premiership," added Bale. "That's very important to me and this is a fantastic opportunity. I've thought long and hard about it and feel the time is right to move on.
"I could have gone in January but I wanted to try and help Saints win promotion. I felt I owed them that and I didn't want to move mid-season.
"I wanted to keep my focus on learning and developing my game at a critical stage of the campaign."
Bale made his debut as a 16-year-old last year for Saints - becoming the second youngest to ever play for the club - and this season he has become a regular for Southampton and Wales.
He's so young and has plenty of time, he'll be a star in the Premiership
He became the youngest Welsh international when he played against Trinidad & Tobago in May last year, setting up a late winner.
Tottenham sporting director Damien Comolli said: "We have been following Gareth for a long time now and have been very tenacious, so we are absolutely delighted to get him here.
"He's a player of great quality and, as we always say, our aim in each window is to improve the quality of the squad. He has the ideal combination to become a top, top player."