England and Nottinghamshire off-spinner Graeme Swann has announced his immediate retirement from cricket.
The 34-year-old has taken only seven wickets during this winter's Ashes series defeat and has ruled himself out of the rest of the tour in Australia.
Swann took 255 wickets in 60 Tests - the sixth highest for England.
"This decision has been very difficult seeing as the England team has been my family for seven years now, but I feel it is the right time," he said.
"I don't regret a single day of my career. Every high has been celebrated with verve and vigour and every low painfully accepted as a chance to learn and improve."
Swann's shock decision comes a week after England lost the Ashes to Australia following a heavy defeat in Perth to give the home side an unassailable 3-0 series lead with two Tests to play.
His retirement means he will be unavailable for the fourth Test, starting in Melbourne on Boxing Day (Thursday), and further unsettles the England team following the departure of batsman Jonathan Trott with a stress-related illness earlier in the tour.
"I know I'm making the decision for the right reasons," added Swann. "My body doesn't like playing five-day cricket any more, and I don't feel I can justify my spot in the team in the latter stages of a game, and as a spinner, that's when you need to come into your own.
"With two games to go in Australia and then a fiercely competitive summer against Sri Lanka and India I feel that it is a great time for someone else to strap themselves in and hopefully enjoy the ride as much as I have," he added.
Swann, who was first named in an England squad back in 1999-2000, finally made his Test debut in 2008 and took four wickets against India in Chennai.
He made a reputation for taking wickets in the first over of a spell and went on to become the sixth-highest wicket-taker in his country's history during this Ashes series.
Despite struggling with elbow problems in recent years, Swann played in three Ashes series victories and helped England become the number one ranked side in the world in 2011.
He also took 104 wickets in 79 one-day internationals after making his debut against South Africa in Bloemfontein in 2000 at the age of 20 and spent a spell as the top ranked ODI bowler in 2011.
In addition, he helped England clinch their first major global world title at the 2010 World Twenty20 in the Caribbean.
"My personal highlights include the three Ashes victories, of which I will cherish for the rest of my life, and the World T20 victory in the West Indies which ranks as my limited overs highlight," he added.
"I have met, played with and against, and become friends with some magnificent people throughout my journey and feel truly privileged to have been given these opportunities.
"If anyone had been in any doubt after the Ashes were
lost with those three thumping defeats, Graeme
Swann's retirement confirms that this is the definitive
end of the era for this England team.
"A huge amount has been achieved - three Ashes series
wins, becoming the number one ranked team in Test
cricket, winning a Test series in India - but the
departure of the pivotal bowler and wise-cracking heart
of the team coming so soon after Jonathan Trott
stepped away with his stress-related illness, marks the
closing of a chapter.
"The question now, with this tour falling apart and a
possible 5-0 'Pomwash' still on the cards, is who might
be next - Andy Flower? Kevin Pietersen?"
Former England captain Michael Vaughan said that Swann has taken the decision "too soon".
He tweeted: "Spinners of his quality are a rare breed. Of all the England players over the last 20 years he is the one the team will miss the most."
Swann's career will stand comparison with his country's greatest players and BBC cricket correspondent Jonathan Agnew has described him as a "true character" who has made a "massive contribution" to England.
Agnew tweeted: "The general feeling was that this might be Swann's last tour, but this is unexpected.
"England's greatest challenge is replacing the man who was the lynchpin to their four-man attack."
England team director Andy Flower has paid tribute to Swann's "outstanding contribution" to the team, adding: "His commitment, competitive spirit and sense of humour have been recognised and admired by team-mates and supporters alike and he has played a big part in England's success over the last five years."
Mick Newell, director of cricket at Nottinghamshire, said Swann's carefree demeanour belied a studious attitude to the game.
"He joined us with a reputation for not taking things seriously but I found him to be very thoughtful about his cricket and very committed to improving his game," said Newell.
"He knows how to perk up a dressing room and he was an outstanding character to have in a cricket team.
"Swanny has been a dominant performer in Test cricket for six years and it will leave a huge gap in the England team because there is no outstanding spinner quite ready to fill the place that he will leave."