QPR midfielder Joey Barton has been banned for a total of 12 matches and fined £75,000 following his dismissal against Manchester City on the final day of the Premier League season.
The Football Association confirmed an independent regulatory commission today found Barton guilty of two counts of violent conduct.
The FA announced Barton received an automatic four-game suspension, with the additional eight matches a consequence of the manner of his dismissal.
QPR had previously announced their intention to carry out their own investigation once Barton's case had been dealt with by the FA.
Barton was shown a red card at the Etihad Stadium for elbowing Carlos Tevez, and he then kicked Sergio Aguero before attempting to headbutt Vincent Kompany.
He denied the charge of violent conduct against Kompany but the FA said the case against Barton was found to be proved.
An FA statement said: "An independent regulatory commission has today dealt with two charges of violent conduct against Joey Barton, arising from the game against Manchester City, resulting in an eight-match suspension and £75,000 fine for the Queens Park Rangers midfielder.
"This eight-match suspension is to run consecutively to the four-game suspension Barton was already given for his dismissal in the fixture, making a total of 12 matches."
Barton's acts were condemned by the chairman of the regulatory commission, who stated: "There are rules of conduct that should be adhered to, and such behaviour tarnishes the image of football in this country, particularly as this match was the pinnacle of the domestic season and watched by millions around the globe."
The Football Association's statement outlined the reasons behind Barton's long ban.
The statement said: "Following Barton's dismissal in the 54th minute of the match, there followed two incidents involving Manchester City's Sergio Aguero and Vincent Kompany. As Barton had already been dismissed, both of these incidents fell outside the jurisdiction of the referee.
"Barton accepted the charge of violent conduct against Aguero but denied the second breach of violent conduct against Kompany. The independent regulatory commission, however, found this second charge proved.
"Barton is already serving a four-match suspension for his dismissal in the match, which consists of three matches for violent conduct plus one match as this was the player's second dismissal of the season.
"The two further breaches for violent conduct ordered he be suspended for eight matches to run consecutively to the four matches, taking the total suspension to 12 matches."
The FA's regulatory panel had discretionary powers to further increase the length of the suspension if charges were found to be proven.
Barton's admission on Twitter that his violent actions were a cynical ploy to provoke a City player to be sent off saw those discretionary powers employed.
Barton insisted via Twitter on the day of his sending-off that he had not lost his head, but that a team-mate "suggested I should try to take 1 of theirs with me".
Speaking earlier this month, QPR chairman Tony Fernandes said: "There are experienced people who will come back to me and we'll review the whole situation.
"Joey has been an integral part of the club and has played his part.
"This is football, and I'm new to it. I don't profess to have all the answers."