Manchester City have signed defender Eliaquim Mangala from Porto for a fee understood to be about £32m.
Mangala has signed a five-year deal.
City boss Manuel Pellegrini said: "He has all of the mental, physical, technical and tactical attributes to become one of Europe's very best defenders."
He added: "Eliaquim is a player I believe will make an immediate impact in the Premier League, thanks to his physicality, his reading of the game and quality on the ball.
"I think he will prove to be a great signing for us."
Mangala was in France's 2014 Fifa World Cup squad but did not play in any games.
"City is a top club in Europe," he told the club's website. "For me, it was an important step to leave Porto and join Manchester City in order to continue my progress.
"I want to win titles and I believe I can do this. I am ambitious and this is why I am here."
He has become City's sixth summer signing and their second from Porto, after Brazilian midfielder Fernando joined for about £12m.
But the deal has taken rather longer to complete than planned.
City posted a video of Mangala online last month, only to remove it. And Pellegrini spoke of the defender as one of the City players who had missed Sunday's Community Shield defeat by Arsenal, even though he had still to be registered.
It has left Mangala short of training ahead of Sunday's Premier League encounter with Newcastle.
"I think I need a little bit of time to be 100%," he said.
"I went on a run every day and trained in the gym. Holidays are great but if the time is too long it is difficult to come back."
Mangala began his career with Standard Liege in 2008, winning the league in his first season, before joining Porto in 2011.
He won two Portuguese titles and made his France debut in a 1-0 defeat by Uruguay in June 2013.
Mangala added: "The fact that Fernando is here is better because I played with him at Porto but there is also other players that I know like Sagna, [Gael] Clichy and [Samir] Nasri."