The British transfer record was smashed on deadline day as an unprecedented January transfer window ended with Premier League clubs having spent £2.8bn during the 2022-23 season.
Chelsea's 121m euro (£107m) deal for Benfica's Argentina midfielder Enzo Fernandez - once confirmed - will take the total expenditure by top-flight clubs in January to a record-breaking £815m.
More than £275m was spent on deadline day alone before the window closed for English clubs at 23:00 GMT on Tuesday.
The deadline day outlay was an increase of 83% on the previous January record of £150m, set in 2018.
And, while an all-time high season expenditure across both the summer and winter windows was guaranteed after a record of £1.9bn was set in September, the final total is double the previous record of £1.4bn in 2017.
The 2018 winter record spend of £430m by Premier League clubs had also already been smashed prior to Tuesday's deadline day, with the eventual total in 2023 an increase of 90% on that - and almost triple the previous January window (£295m), according to financial services firm Deloitte.How transfer deadline day unfolded
The Premier League's financial dominance in Europe increased to the highest proportion ever reported, as the spending by English top-flight clubs accounted for 79% of the total across Europe's 'big five' football leagues, where January spending fell by 35% from 2022 to €255m (£225m).
Indeed, Chelsea spent more in January - around £288m - than the combined total of all clubs in the Bundesliga, La Liga, Serie A and Ligue 1.
Among English Football League clubs, spending rose to £25m, up from £20m in the previous winter window.
However just 3% of Premier League clubs' total outlay (£25m) was spent on acquiring players from the EFL, with a record 85% spent on talent playing outside the UK.
Tim Bridge, lead partner in Deloitte's Sports Business Group, said: "The record spending by Premier League clubs this season is beyond anything that we've seen before.
"Premier League clubs have outspent those within the rest of Europe's 'big five' leagues by almost four to one in this transfer window, allowing them to hold on to their key players, while attracting top-talent from overseas.
"However, while there is a clear need to invest in squad size and quality to retain a competitive edge, there will always be a fine balance to strike between prioritising success on-pitch and maintaining financial sustainability.
"The decline in spending across the English football system is likely to be of growing concern for members of the EFL and could further fuel the debate around distributing finances more evenly across the pyramid."
What deals were done on deadline day?
Chelsea's late capture of Fernandez was the headline deal on deadline day as the Blues smashed the British transfer record - previously the £100m Manchester City paid for Jack Grealish in 2021 - to land the 22-year-old World Cup winner.
Elsewhere, Tottenham announced the signing of full-back Pedro Porro from Sporting Lisbon on loan until the end of the season, with an obligation to buy for 45m euros (£40m) - while defenders Matt Doherty (permanent) and Djed Spence (loan) were allowed to leave.
Premier League leaders Arsenal strengthened with the £12m acquisition of Italy midfielder Jorginho from Chelsea, while fourth-placed Manchester United completed the loan signing of Austrian midfielder Marcel Sabitzer from Bayern Munich.
Southampton ended the window with a late flurry of activity, completing a club record £22m deal for Ghana winger Kamaldeen Sulemana as well as signing Nigeria striker Paul Onuachu.All the Premier League and EFL January transfer window dealsThe transfer window that changed women's footballVisit your Premier League club's page for all the latest news, analysis and fan views - and get news notifications
Bournemouth signed Ukraine centre-back Illia Zabarnyi for a reported £24m and Ivory Coast midfielder Hamed Traore on an initial loan before a £20m summer move.
Fellow promoted side Nottingham Forest were also busy, completing deals for Atletico Madrid's Brazilian defender Felipe and Newcastle midfielder Jonjo Shelvey for undisclosed fees, while Paris St-Germain goalkeeper Keylor Navas arrived on loan.
Leicester City signed defender Harry Souttar from Stoke City in a deal which could rise to £20m with add-ons, and Crystal Palace signed France youth international Naouirou Ahamada from Stuttgart for 11m euros (£9.7m).
A surprise high-profile Premier League departure saw Manchester City full-back Joao Cancelo join Bayern Munich on loan for the rest of the season, with a 70m euro (£61.5m) option to join permanently in the summer.
What were the biggest transfers of the January window?
Chelsea's deal for Fernandez was a fitting end to another astonishing window. Amid another remarkable spending spree, the Blues agreed a £89m deal with Shakhtar Donetsk for 22-year-old Ukraine forward Mykhailo Mudryk earlier in January.
In addition to their deadline day signing of Jorginho, Arsenal signed Belgium striker Leandro Trossard from Brighton for £21m plus add-ons, along with Jakub Kiwior from Serie A side Spezia for 20m euros (£17.6m).
Elsewhere, Liverpool agreed a deal worth 40-50m euros (£35.4m-£44.3m) to sign Netherlands forward Cody Gakpo, 23, from Dutch club PSV Eindhoven.
And Newcastle United's signing of 21-year-old Anthony Gordon from Everton could eventually be worth £45m.Deadline day on social: Chelsea spending big and Cancelo shown the exitQuiz: Name the Premier League's previous 25 most expensive January signings
There was big money spent among the league's current bottom-half sides too, with Leeds United signing French forward Georginio Rutter, 20, from Hoffenheim for a club record 40m euros (£36m).
Bournemouth also recruited Burkina Faso winger Dango Ouattara from Lorient for around £20m and Leicester paid £17m for defender Victor Kristiansen
Following the £15m sale of Danny Ings to West Ham, Aston Villa signed teenage Colombia striker Jhon Duran from Chicago Fire for £18m.
Big-movers Chelsea dominate Premier League spendingTransfer Deadline Day: Chelsea signings could be difficult for Graham Potter
It has been an extraordinary couple of transfer windows for Chelsea since the club's £4.25bn sale to a consortium led by American investor Todd Boehly last May.
And it looked that way even before an eye-watering amount was finally agreed with Benfica for Fernandez late into deadline day.
It is the latest bold statement of intent in the still early days of Chelsea's new era under Boehly, which has seen more than £550m spent on new signings.
Their spending in January alone exceeded £300m on eight new players, with Mudryk, Malo Gusto (£30.7m), Benoit Badiashile (£35m), Noni Madueke (£30.7m), Andrey Santos (£18m) and David Datro Fofana (£8m-£10m) all also added on permanent deals.
Meanwhile, talented 23-year-old Portugal forward Joao Felix moved to Stamford Bridge on loan from Atletico Madrid at a cost of 11 million euros (£9.7m).
That came after a summer that saw them spend a Premier League record £270m - the second-highest summer spend by any club in the world after Real Madrid (£292m) in 2019.
In total, Chelsea accounted for 37% of the total amount spent by Premier League clubs in January.
'European Super League has arrived - it is in England'
Spanish football journalist Guillem Balague on BBC Radio 5 Live's Football Daily
[Chelsea's spending] is impressive, isn't it. Something that says the European Super League has arrived...and it's based in England. This is where managers want to be and where players want to be.
What has happened with the Mykhailo Mudryk case, where Chelsea have doubled the wages Arsenal were offering, that kind of thing can only happen in England.
There is no turning back. La Liga is making a big effort to maximise the potential of the competition, but it is still miles away from the Premier League.
It's something people have to accept and adapt to. If the fact that every time you bring through a player with a little bit of quality he goes to the Premier League, keep at it.
There is a limited number of players you can sign, despite what Chelsea are doing, so, yes, the other European leagues need to sell themselves in a different way.
The January deals that never were
Despite all the money spent, not everyone got what they wanted.
Morocco forward Hakim Ziyech's proposed deadline day move from Chelsea to PSG appeared to collapse as the player waited in Paris because the documentation to complete the transfer was not submitted in time.
Arsenal had a £60m bid rejected by Brighton in their pursuit of midfielder Moises Caicedo, despite the midfielder confirming his desire to leave the club in an open letter on his Instagram. That came after the Gunners were beaten to the signing of Mudryk by Chelsea.Have Arsenal done enough in January to win the Premier League?Wednesday's transfer gossip: Manchester City plan move for Leicester's James Maddison
England midfielder Conor Gallagher decided to stay at Stamford Bridge despite interest from Premier League strugglers Everton.
Indeed, despite appointing former Burnley boss Sean Dyche as the club's new manager on Monday, the 19th-placed Toffees did not do any business on deadline day.
But, after all the excitement, who do you think was the best big-money signing of the 2022-23 January transfer window? Have your say below.
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