West Ham have completed the signing of defender Emerson Palmieri from Chelsea for a fee in the region of £15million.
The Italy international has penned a four-year deal with the Hammers, with the option of a further 12 months, and will wear the number 33 shirt at the London Stadium.
Emerson becomes David Moyes' seventh signing of the transfer window, following the arrivals of Nayef Aguerd, Alphonse Areola, Flynn Downes, Gianluca Scamacca, Maxwel Cornet and Thilo Kehrer.
The 28-year-old struggled to establish his place in Chelsea's starting line-up after moving from Roma in January 2018, spending last season on loan at Ligue 1 side Lyon.
Nevertheless, the left-back brings plenty of experience to the West Ham ranks, having started for Italy in their Euro 2020 final victory over England last year.
"I'm very happy to be here and to arrive here. It's a big challenge for me, it's a big team, so I'm very happy to be here and I'm ready," Emerson told the club's official website.
"Personally, since the first day I arrived here in England, I always saw the big clubs and I always watched the big games, and I knew the history about West Ham.
"The history is so, so big for this team and so when I knew about the interest, for sure I said 'Yes, let's go, I want to go there' and I'm here now! I can't wait to get started in a West Ham shirt."
Hammers boss David Moyes added: "We are very pleased to welcome Emerson to West Ham United.
"He is an experienced player with a good pedigree, who has enjoyed great success at both club and international level in recent years.
"He will give us strong competition in defensive areas and brings a winning mentality that we are looking to build here at West Ham."
West Ham have started their league campaign with three defeats and no goals scored for the first time since 1971-72.
The Hammers take on Viborg in the second leg of their Europa Conference League play-off on Thursday, leading 3-1 from the first leg, before facing Aston Villa in the Premier League three days later.