England manager Martin Johnson stepped down on Wednesday after a 3-1/2-year stint in charge culminated in a rugby World Cup campaign dogged by problems on and off the pitch and a miserable quarter-final exit.
Johnson, 41, told a news conference he would not be renewing his contract when it expired at the end of this year.
I've given this a huge amount of thought since our return from the World Cup...and I haven't come to this decision lightly, he said.
I think it's in the best interests of myself and the England team that I don't carry on into next year.
The cycles are from World Cup to World Cup and you have to decide whether you are prepared to jump in for four years and wholly commit yourself to that job and weigh it up. I'm not.
Johnson hinted that his decision, which comes while the Rugby Football Union (RFU) is conducting a series of reviews into its own governance and the World Cup performance, may have been a case of jumping before he was pushed.
It's been my call and I understand that if I hadn't made it then maybe someone would have made it for me, he said.
Johnson, England's 2003 World Cup-winning captain, was appointed in 2008 after the sacking of Brian Ashton even though he had no coaching experience.
After a difficult first two years he steered England to their first Six Nations title in eight years last season but was always going to be judged on the World Cup.
A series of unwanted front-page headlines accompanied England's underwhelming World Cup campaign with stand-in captain Mike Tindall subsequently thrown out of the elite player squad and handed a hefty fine for his off-field antics.
Tindall, married to Queen Elizabeth's granddaughter Zara, was photographed drinking with a mystery blonde in a bar in Queenstown during the tournament.
Johnson controversially selected flyhalf Toby Flood at centre -- dropping Tindall -- for the quarter-final, saying for the first time on Wednesday that the furore surrounding the player might have had an influence on him not being picked.
At the time Johnson defended Tindall and his team mates, who had permission to go drinking that night, and was now unsure how much of an impact the distractions had made.
How that affected performances on field no one can answer, he said. The off-field stuff didn't help. It portrays the team in a bad light and not in an accurate light. But we gave people the opportunity to report things as they did.
I don't know about being let down (by his players). Of course it didn't help, we didn't want that reputation.
In the quarter-final Johnson saw his previously watertight defence leak 16 unanswered points in the opening half-hour against a French team who had previously been humiliated by Tonga.
England returned home to a cascade of criticism after equalling their worst World Cup finish and Johnson, whose team had won all their pool games and had the best defensive record of the group stage, was very much in the firing line.
It's disappointing because we knew we were a better team than the one who played in that quarter-final, Johnson said. Even at 16-0 we still could have come back and won that game.
Winning those matches is about executing under pressure and that's what let us down.
This is not a losing team, we won the Six Nations, won 10 of 13 games this year.
Speculation about a replacement for Johnson has been clouded by internal chaos at the RFU, with former chairman and acting CEO Martyn Thomas leaving next month.
Professional rugby director Rob Andrew said there would be no decision until after the reviews, adding that he respected Johnson's decision not to carry on.
It's not for us to judge how or why he made the decision. It's not what he wants to do going forward, he told the news conference. That was the deal with this, with Martin, to do the World Cup, then come back and everybody think about what's happened.
Andrew's own position has also been uncertain amid the reviews but he said he was absolutely not considering resigning.
Former Italy and South Africa coach Nick Mallett said later he had ruled himself out of the England job because he wanted to spend time with his family in Cape Town.
In a statement issued by his management company, Mallett said he had been approached by the RFU to see if he would be available should Johnson resign.
I had previously expressed my interest in the position publicly and was interested to hear what the RFU representatives had to say, he said.
After mulling it over for a few days and discussing the opportunity with close friends and family, I have decided that I will not be making myself available for the position and I have disclosed this to the RFU.
The bookmakers' favourite is Jim Mallinder, who steered Northampton to the Heineken Cup final last year and who previously coached England's second-string Saxons team with great success.
(Editing by Ken Ferris, Sonia Oxley and John Mehaffey)