Answers to four key questions about Chelsea's record-breaking January spending spree
The signing of Enzo Fernandez from Benfica for £106.8million in the final hours of the January transfer window capped an astonishing month for Chelsea.
That they should have broken the British transfer window to sign the World Cup-winning Argentina midfielder was a fitting way to sign off owner Todd Boehly's whirlwind spree, with total spend since he took over last May eclipsing even the club's most spendthrift rivals over the same period.
Here, Planet Sport takes a look at who has come though the door, what it has all cost and, crucially, how they have pulled it off amid UEFA's strict spending rules.
Who did they buy in the summer?
The manic transfer activity began in July when Raheem Sterling was offered a way out of Manchester City and Kalidou Koulibaly was signed to fill the gap left by defensive departures during the summer.
Marc Cucurella and Wesley Fofana arrived from Brighton and Leicester respectively in August to complete the restructuring of the team's back line, while a deadline-day deal to sign Pierre-Emerick Aubameyang from Barcelona was rushed through partly at the behest of now-departed head coach Thomas Tuchel.
Less high-profile but nevertheless pricey youngsters Carney Chukwuemeka, Cesare Casadei and Gabriel Slonina were signed with an eye on the future, with 19-year-old Omari Hutchinson arriving on a free from Arsenal. Dennis Zakaria was signed on loan from Juventus until the end of the season with an option to buy.
And how about in January?
Characteristically a quieter time transfer-wise for most clubs, Chelsea have gone into overdrive with a total of eight signings, beginning with the capture of defender Benoit Badiashile from Monaco in the first week of January.
Ivory Coast striker David Fofana arrived from Norwegian club Molde, while 18-year-old Brazilian midfielder Andrey Santos came in from Vasco de Gama.
Possibly the biggest story of the window prior to deadline day was the club's hijacking of Arsenal's deal for Mykhailo Mudryk, while the loan signing of Joao Felix from Atletico Madrid was another Gunners target that the Blues stole away.
England Under-21 international Noni Madueke came in from PSV Eindhoven, defender Malo Gusto signed from Lyon before being loaned back to the Ligue 1 side, then Fernandez headlined deadline day and the January window by breaking the British transfer record.
How much have they spent?
The £105m for Fernandez has dragged up an already unprecedented spend under Boehly to something truly astronomical, adding to the £88m forked out to Shakhtar Donetsk for Mudryk and the £70m for Fofana.
Other fees to catch the eye include £47.5m for the 28-year-old Sterling and £33m for 31-year-old Koulibaly, particularly so when one considers neither player is likely to have much sell-on value. Cucurella, younger at only 24, cost £56m.
Badiashile at £35m means the team have brought in seven players for £30m or more since the summer, bringing the total spend to somewhere in the region of £550m.
How does this square with Financial Fair Play rules?
It is all to do with the way UEFA assesses clubs' annual spending. Rather than record the entire fee spent on a player as outgoings for a given year, the figure is instead spread over the term of the player's contract.
That means that, for example, a £50m deal for a player who is given a five-year contract will be treated by the governing body as a £10m spend per year for the duration of the contract, rather than £50m in the year the transfer was made.
This explains why Chelsea have taken the unusual step of handing out seven and eight-year contracts to their big-money signings, reducing the total amount recorded as transfer spending per season.
However, reports suggest UEFA is set to close this loophole in the summer and enforce contract limits of five years - something which may have persuaded the Blues to go all out to sign Fernandez before Tuesday's deadline.