Chelsea have announced the signing of defender Marcos Alonso on a five-year contract from Italian side Fiorentina for a fee believed to be in the region of £23 million.
The Spanish full-back returns to England after an earlier spell with Bolton before moving to Serie A in 2013, where he has made just over 50 appearances for the Viola.
"I'm very happy," the 25-year-old told his new club's official website. "It's a step up in my career and I think this is the perfect place for me to continue developing. It's time for me to win some titles.
"It was an easy decision for me to make when I heard the club were interested in signing me.
"My family and close friends know Chelsea is the club I have dreamed about playing for so I'm really excited about the challenge and I'm looking forward to working with my new team-mates."