Declan Rice has joined Arsenal from West Ham for a club-record cost of £105 million.
The Gunners had two bids for the 24-year-old rejected, one for £80 million and another for £90 million, before agreeing to a £105 million agreement with the London club.
The England midfielder will now earn about £250,000 per week in north London after signing a five-year contract extension with Arsenal until 2028.
He becomes Arsenal's third signing of the summer after the £65m arrival of German playmaker Kai Havertz from Chelsea, and £40m arrival of Ajax defender Jurrien Timber.
His move to the Emirates Stadium brings a decade-long spell at West Ham to an end, rising from a youth-team player to club captain.
He made 245 appearances for the Hammers after making his first-team debut in 2017 and his final game for the club saw him lift West Ham's first trophy in 43 years by winning the Europa Conference League final.
The £105m Rice deal is broken down into an initial payment of £100m, which will be paid over 24 months, with £5m in add-ons, which are £1m every time Arsenal qualify for the Champions League and Rice starts 60 per cent of games.
Speaking to the Arsenal website, Rice said he was determined to take his game to another level with the Gunners and praised the club's manager Mikel Arteta.
"In football, amazing opportunities arise. Big clubs, like Arsenal, have come for me and it's really hard to turn down," Rice said.
"You only ever get one career and I really believe in what Mikel is building here and the squad he's building. I'm really looking forward to the future with Arsenal.
"With Mikel and how he works, the squad, how young everyone is, the energy around the club and also the challenge of getting Arsenal back to where they belong, that means a lot to me.
"I know the fans really want that. For me as a player, I've come here really hungry to have more success and to spend my best years at this great club.
"I know he [Arteta] is going to get the best out of me. I know I've got more levels to go up in my game, and I feel like he's the manager to take me to those next levels. I am really excited to be working with him."
Arteta told the club's official website: "We're really happy that Declan is joining us. He is a player with tremendous ability, who has been performing at a high level in the Premier League and for England for a number of seasons now.
"Declan is bringing undoubted quality to the club and he is an exceptional talent who has the potential to be very successful here.
"Declan has great experience in the Premier League at only 24 years old. He has captained a very good West Ham team and as we all saw, he recently lifted a European trophy.
"The responsibility and role he has taken on has been very impressive and we are really excited that he is joining us."
Meanwhile, Arsenal sporting director Edu said: "Declan is a player with fantastic ability and a proven record at both club and international levels. The process of this transfer has been a big team effort with a clear plan, and we are so happy that Declan is joining us.
"Declan is a high-quality, young international player who will add great strength to our squad, fitting so well into our strategy of competing with young talented players at the centre of our club.
"It's great that Declan will be joining up with Mikel, our coaches and his new teammates in good time ahead of the new season."