Tottenham have signed MK Dons midfielder Dele Alli on a five-and-a-half-year deal for an initial £5m fee.
The 18-year-old will be loaned back to the League One side for the rest of the season as part of the deal.
Spurs have also released defender Benoit Assou-Ekotto from his contract, which was set to expire in June.
England Under-19 international Alli, who was also wanted by Newcastle United, has scored 12 goals in 25 league games for MK Dons this season.
"It's a massive club and I'm really happy to be here. I'd love to play for Spurs and at White Hart Lane," he said.
"It won't be easy and I'll have to fight for my place in the team but I'll work hard to do that."
Milton Keynes-born Alli made his Dons debut as a 16-year-old in November 2012 after progressing through the club's youth set-up.
The midfielder, who has also been watched by Liverpool and Bayern Munich, marked his second appearance by scoring against Cambridge City in an FA Cup tie.
He signed a contract with MK Dons until 2017 in September.
Left-back Assou-Ekotto, who joined Spurs from Lens in 2006, had not played for the club since May 2013, and spent last season on loan at Queens Park Rangers.