Manchester United have completed the signing of defender Victor Lindelof from Benfica for £31m.
The Sweden international, 22, travelled to Manchester on Wednesday to discuss terms and have a medical.
Lindelof, who has won 12 caps for Sweden, becomes United's most expensive defender, overtaking the £29.1m paid for Rio Ferdinand in 2002.
"I'm thrilled," said Lindelof, who joins on a four-year contract with an option for a fifth year.
The centre-back made 47 appearances as Benfica won a Portuguese domestic double last season.
"I have enjoyed my time at Benfica enormously and I have learned a lot there," he said. "But I'm looking forward to playing in the Premier League at Old Trafford and for Jose Mourinho.
"I'm keen to get started and make my contribution to the team's efforts to win more trophies."
Mourinho said: "Victor is a very talented young player, who has a great future ahead of him at United.
"Our season last year showed us that we need options and quality to add depth to the squad and Victor is the first to join us this summer."
BBC Sport's Simon Stone
United have struggled for consistency in central defence since Sir Alex Ferguson retired in 2013.
For a couple of months last season, Phil Jones and Marcos Rojo did so well that Mourinho put off a proposed January move for Lindelof.
Both picked up injuries, though, as did Chris Smalling. Daley Blind was excellent in last month's Europa League final but he does not have the stature Mourinho demands from his central defenders.
At 6ft 2in, Lindelof does. And, at 22, he is only a year younger than Rio Ferdinand was when he made the switch to Old Trafford from Leeds.
If Lindelof, who has been signed in preference to Burnley's Michael Keane, can get close to showing the poise that Ferdinand brought to Ferguson's team, Mourinho will have got himself an outstanding foil for one of last season's new arrivals, Eric Bailly.
Mourinho intends to bring in four players this summer.
Talks are continuing with Real Madrid over forward Alvaro Morata, although there is still no agreement on the fee.
The same is also true of Inter Milan's Ivan Perisic.
United representatives met their Inter counterparts last week but their respective valuations remain a long way apart.
Inter are looking for a fee of about £44m for the 28-year-old Croatian winger, who joined them for £14m from Wolfsburg in 2015. United value the player at £30m.
One player United have been linked with who will not be moving to Old Trafford is Monaco full-back Fabinho.
It is understood Mourinho has no interest in the Brazilian.
Find all the latest football transfers on our dedicated page.