Romelu Lukaku has returned to Chelsea after the European champions signed the Belgium forward from Inter for a reported £97.5million (€115m) fee.
After winning the Champions League, Chelsea have been in the hunt to further bolster Thomas Tuchel's squad with the acquisition of a top-tier striker.
Erling Haaland was a target, but Chelsea saw their approach rebuffed by Borussia Dortmund, who are in no need to sell the Norwegian star after they brought in €85m (£72.6m) for Jadon Sancho.
Chelsea subsequently switched their focus to Lukaku, who led Inter to their first Serie A title in a decade last season, netting 24 league goals.
An initial offer was reportedly turned down but, after Lukaku – who had earlier claimed he wanted to stay at San Siro and play under new coach Simone Inzaghi – indicated he wished to leave, Inter opted to sell their prized asset.
"I'm happy and blessed to be back at this wonderful club," Lukaku told Chelsea's website. "It's been a long journey for me: I came here as a kid who had a lot to learn, now I'm coming back with a lot of experience and more mature.
"The relationship I have with this club means so much to me, as you know. I have supported Chelsea as a kid and now to be back and try to help them win more titles is an amazing feeling."
Chelsea have by no means signed the 28-year-old cheaply, however, with the reported fee a club record.
It also falls just £2.5m short of the British transfer record set by Jack Grealish's switch to Manchester City. Lukaku has signed a five-year deal to head back to Stamford Bridge.
Lukaku's departure will come as a blow to Inter but does relieve some of the financial pressure on the Italian giants, as they needed to raise funds through player sales.
Achraf Hakimi has left to join Paris Saint-Germain, while Lautaro Martinez has also been touted as potentially leaving, though Inter would surely be loath to lose both of their forwards in the same transfer window.
Lukaku joined Everton on a permanent basis in 2014 after enjoying a stellar campaign on loan with the Toffees.
He had signed for the Blues as a teenager in 2011 from Anderlecht, though his first-team outings were limited before he went on to join West Brom on loan.
Lukaku became Everton's record Premier League goalscorer, netting 68 times before joining Manchester United for £75m in 2017.
Despite a promising start at Old Trafford, Lukaku failed to find his best form under Jose Mourinho. Ole Gunnar Solskjaer allowed him to leave for Inter in 2019, a move that reignited his career.
Having thrived under Antonio Conte, Lukaku now rejoins Chelsea as one of the world's leading players at his position.