Everton have announced the signing of Michael Keane in a deal that could reach a club-record fee of £30million.
The England international defender has penned a five-year deal at Goodison Park.
Everton have paid an initial £25m to the Clarets, with a potential £5m more to come, which would match the Toffees' record outlay, the fee they spent to bring Romelu Lukaku to the club from Chelsea.
Having become Burnley's most expensive player in history, Keane said the chance to work with former Netherlands and Barcelona defender Ronald Koeman was too good to turn down.
"I'm absolutely delighted to be at Everton, a fantastic football club with passionate fans and a great tradition and I can't wait to come into training tomorrow to meet all the lads," Keane said.
"First and foremost, the manager was a big factor in me coming to the club. He played in my position when he was a world-class player for a great Barcelona side and a great Dutch side and the style of football he likes to play will suit me, I believe.
"I watched a lot of Everton last season and I believe I really suit how the team likes to play. I feel like this is a great place to come and continue my development as a player.
"He's convinced me that he can still improve me in certain areas of my game. I'm only 24 which, for a centre-half in the Premier League, is relatively young. I've still got a long way to go and I know this and hopefully under his guidance I'll keep improving."
Keane, who had a year left on his Turf Moor contract, had been linked to previous club Manchester United before Victor Lindelof's move from Benfica, with Liverpool also reportedly interested in signing the 24-year-old.
But Everton stole in to snap up the centre-back, who received his first two England caps during the March international break, playing against Germany and Lithuania for Gareth Southgate's side.
Keane's arrival adds to the close-season spending at Everton, who have already brought in goalkeeper Jordan Pickford from Sunderland, Netherlands midfielder Davy Klaassen from Ajax and Sandro Ramirez from Malaga.
The club may, however, have a battle to hold on to star striker Lukaku, who hit 25 Premier League goals last season and has been linked with a return to former club Chelsea.