Manchester City have signed French defender Aymeric Laporte from Athletic Bilbao for a club record fee of £57m.
The fee for Laporte, yet to win a cap for France, takes spending by Premier League clubs this month to £252m - a record for a January transfer window.
The 23-year-old's arrival takes City manager Pep Guardiola's spending on defenders and a goalkeeper since the end of last season to £215.5m.
The club's previous record fee was the £55m paid for Kevin de Bruyne in 2015.
The centre-back has played 19 times for France at Under-21 level.
"I am looking forward to working under manager Pep Guardiola and trying to help the club to achieve success," he told the City website.
"It means a lot that the club have shown faith in me and I am excited to get started."
Concern about skipper Vincent Kompany's injury record and uncertainty over the reliability of Eliaquim Mangala led Guardiola to believe he required another central defender in addition to current first choices John Stones and Nicolas Otamendi.
In a news conference on Tuesday to preview Wednesday's Premier League match against West Brom, the City boss defended the club's spending in 2017-18's two transfer windows.
"I understand the criticism, but we have spent £300m on six players," said Guardiola, adding the £43m spent on midfielder Bernardo Silva to the outlay on defensive players.
"Others have done it on two. We had a lot of older players out of contract. To compete we needed to spend. A club can decide to spend on two players. We did it in a different way.
"We understand the inflation of the market. We have spent on six players and others have done it in one or two. We accept criticism, but more important is that they play well."
Guardiola also said France defender Mangala would remain at the club.
|City's defensive spending 2017-18|
|Benjamin Mendy (left-back) - £52m|
|Ederson (goalkeeper) - £35m|
|Kyle Walker (right-back) - £45m|
|Danilo (full-back) - £26.5m|
|Aymeric Laporte (centre-back) - £57m|
He is a Guardiola type of player, so good on the ball. He carries the ball into midfield; he is perfect for City and City are perfect for him.
City were ready to pay 60m Euros for him in 2016, but he said he was not ready and he wanted to stay at Bilbao. Now 18 months later, he feels ready.
He knows now is the time - the World Cup is in six months but he has not been capped by France yet.
France boss Didier Deschamps is sceptical about him, especially physically. That is the only question mark over him coming to the Premier League. He will face different types of strikers than in Spain.
He has only been called up once by France and he is even considering switching allegiance to Spain, for whom he qualifies through residency.
Top-flight clubs smash January record
City's £57m capture of Laporte moved the total spent by Premier League clubs in this window from £195m to a record £252m.
The previous high of £225m was set in 2011, when Liverpool striker Fernando Torres moved to Chelsea on deadline day.
Chile forward Alexis Sanchez's move from Arsenal to Manchester United has been the story of the window so far, despite no fee being involved as he made the switch in a straight swap for Armenia playmaker Henrikh Mkhitaryan.
The biggest fee so far is the £75m Liverpool paid to Southampton for Netherlands centre-back Virgil van Dijk - a world record for a defender.
The story 12 months ago
In January 2017, a six-year high of £215m was spent by Premier League clubs in 162 completed deals.
But for the first time, Premier League clubs recorded a transfer window profit - bringing in £40m more than they paid out.
However the top six clubs spent just £40,000 during the window and, while Gabriel Jesus arrive at Manchester City that month, he had already signed from Palmeiras in August 2016.
Other big transfers included Morgan Schneiderlin's move from Manchester United to Everton (£20m) and Wilfred Ndidi transferring from Genk to Leicester City (£15m).
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