London: Premier League bad boy Joey Barton has joined top-flight newcomers QPR on a four-year contract from Newcastle United, the London club announced on Friday.
The 28-year-old was pictured on the QPR website holding the number 17 shirt that he will wear this season.
"It's been quite a whirlwind, so to get things finally sorted and draw a line under it all is a great relief," Barton told the site.
"There's obviously a great set of lads here already and that's why they had such a great season in the Championship (second division)."
"The gaffer is talking about adding two or three more bodies and that, combined with the potential of the club and the new owners' ambitions, bodes really well for the future."
Barton, who has one England cap, underwent a medical with QPR on Thursday but then informed his followers on Twitter that he needed "time and space" to think about his future.
He had fallen from grace with the Newcastle management in recent weeks after publicly criticising the club's transfer policy in light of the departures of Kevin Nolan and Jose Enrique.
Newcastle subsequently announced that Barton was available on a free transfer.
With Barton having previously stated that he would only leave St James' Park for a Champions League club, QPR coach Neil Warnock said his signature was a real coup.
"We've got a very, very good player on our hands," said Warnock.
"He's coming here to show people what he can do. He wants to get back into the England team."
"He's very enthusiastic. People will say one or two things about him but they've said stuff about me in the past too, so I won't worry about that."
Barton joined Newcastle from his formative club Manchester City in June 2007 and spent four years in the north-east, making 84 appearances in all competitions and scoring eight goals.
Despite his talent, the Liverpudlian's career has been dogged by controversy.
In May 2008 he was sentenced to six months imprisonment for common assault and affray over an incident outside a McDonald's restaurant in Liverpool.
He served 77 days of this prison term, during which time he was given a four-month suspended sentence over a vicious training ground attack on former City teammate Ousmane Dabo in May 2007.
More recently he has become something of a cult figure in England after setting up a Twitter account (@Joey7Barton) that has attracted over 460,000 followers.
In a tweet on Wednesday, he wrote: "Don't want to leave Newcastle........I've made that clear but my hands are tied."