Newcastle United have signed Inter Milan defender Davide Santon on a five-year deal.
The two clubs were understood to have agreed a fee in the region of £5m for the 20-year-old Italy international.
"Davide is a young lad and a great signing," said Newcastle manager Alan Pardew. "I am sure he will adapt to the Premier League very quickly."
The Magpies have also completed the signing of Charlton goalkeeper Rob Elliot, also on a five-year contract.
"He is a quality left-back and an established international who gives us flexibility in defence."
Santon added: "I am really pleased to sign for Newcastle. The chance to play in the Premier League and in front of 50,000 fans at St James' Park was too good to turn down."
"This is an ambitious club who want to move forward and I want to help them achieve that."
Newcastle had been criticised after sales of Joey Barton, Kevin Nolan, Jose Enrique and Andy Carroll.
But managing director Derek Llambias said: "The signing of Davide Santon is a real coup for this club.
"It confirms our commitment to bringing quality players whose best years are head of them to St. James' Park."
Santon spent the second half of last season on loan at Cesena after falling out of favour at Inter, initially under former manager Jose Mourinho.
Pardew has been searching for a full-back since Jose Enrique left for Liverpool in a £6m deal and has now secured the servies of Santon, described as 'the new Paolo Maldini' earlier in his career, who has won seven international caps for Italy.
The Newcastle boss was also keen to add another goalkeeper as Netherlands international Tim Krul and Steve Harper were his only senior shot-stoppers following Fraser Forster's season-long loan move to Celtic.
A £100,000 bid for Elliot was turned down by Charlton before the Premier League side finally got their man for an undisclosed fee.
The 25-year-old, who also spent time on loan at Notts County and Accrington, made his Charlton debut at Plymouth in April 2008.