Here's a look at the top five most costly defenders of all time
Harry Maguire, £80 million, Leicester to Manchester United (August 2019)
The England centre-back was top of Manchester United's transfer window shopping list after their defensive woes last season and boss Ole Gunnar Solskjaer finally got his man with a fee so huge that even big-spending Manchester City bowed out of the race to sign him.
Virgil van Dijk, £75 million, Southampton to Liverpool (January 2018)
Liverpool paid Southampton a then world-record fee for a defender to sign the Netherlands centre-half and Van Dijk has proved a huge success, helping Liverpool reach two Champions League finals.
They won the second of those, against Tottenham, to be crowned European champions for a sixth time.
Lucas Hernandez, £68 million, Atletico Madrid to Bayern Munich (July 2019)
The France international moved to Spain at the age of four and joined Atletico Madrid's junior set-up.
Hernandez became a World Cup winner in 2018 and made more than 100 appearances for Atletico before joining Bundesliga champions Bayern at the end of last season.
Matthijs De Ligt, £67.5 million (could rise to £77 million with potential add-ons), Ajax to Juventus (July 2019)
De Ligt made his Ajax and Netherlands debut aged 17, quickly making the switch from deep-lying midfielder to centre-back.
De Ligt played more than 100 games for Ajax and captained a youthful side to the semi-finals of the Champions League last season before joining Italian champions Juventus a month before his 20th birthday.
Aymeric Laporte, £57 million, Athletic Bilbao to Manchester City (January 2018)
The French centre-half joined Athletic Bilbao at the age of 16.
Also able to play left-back, Laporte made more than 200 appearances for Bilbao before Manchester City signed him for a then club-record fee in January 2018.
He has since won two Premier League titles at City, as well as League Cup and FA Cup winners' medals.