Atletico Madrid have signed England midfielder Conor Gallagher from Chelsea for a fee believed to be in the region of £33m.
The 24-year-old has signed a five-year contract with the Spanish top-flight club.
Gallagher joined Chelsea at the age of six and went on to make 90 appearances, scoring 10 goals.
He had entered the final year of his contract at Stamford Bridge so Chelsea wanted to sell now to avoid losing him on a free transfer next summer.
"To everyone at Chelsea, thank you for making my dreams come true," Gallagher wrote on Instagram.