Arsenal have confirmed the signing of Declan Rice from West Ham for a reported £105million fee.
The England international has signed a long-term deal in North London after his Hammers departure was confirmed earlier on Saturday.
Manager Mikel Arteta said: “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."
Rice's arrival further reinforces Arteta's squad, with Jurrien Timber joining from Ajax on Friday to add to Kai Havertz's switch from Chelsea last month.
The 24-year-old will look ahead to playing Champions League football for the first time in his career following Arsenal's second-place finish last season.
Rice said: "Mikel Arteta is a massive factor in the reason why I’ve come here.
"I’m so excited — he speaks for himself. You see how he works — you also got a real insight into how he works on the Amazon documentary. He’s a top coach."
Rice will wear the No41 shirt at his new club — the same number he donned at West Ham.
Rice departs the Hammers on a high having captained his boyhood club to victory in the Europa Conference League last month.
Announcing Rice's exit, co-chairman David Sullivan said: "I am sorry to see Declan leave us, but I believe that everyone at West Ham United should be very proud of the part we have played in his journey.
"I would like to make it clear to our supporters that we did not want to sell Declan.
"We wanted to build our team around him and made a series of improved, long-term contract offers to secure his future.
"However, once Declan made it clear that he wished to move on and seek a new challenge, the club felt it would not be right to stand in his way, acting in the best interests of West Ham United."
David Moyes' Irons will now seek to reinvest the huge sum in finding a replacement for Rice, with Southampton skipper James Ward-Prowse linked with a switch to the London Stadium.
