England manager Martin Johnson has stood down after three-and-a-half years in the role.
Johnson's decision follows a miserable World Cup which ended in quarter-final defeat by France and also featured a series of off-field controversies.
"I think it is in the best interests of both the England team and myself not to carry on," said the 41-year-old.
"I have a choice at the moment. If I hadn't made that decision someone may have made it for me."
Johnson won 84 caps for England as a player, leading the side to victory in the 2003 World Cup, but during his time as manager England won only 21 of the 38 matches played.
"While we've had our most successful season with 10 wins from 13, we are disappointed with how we ended it with the World Cup. I think it's the right decision at this time. It's a thoughtful and considered opinion," continued Johnson, who had no previous top-level coaching experience when appointed.
"Part of me regrets leaving the job in these circumstances. There is unfinished business and a feeling to put things right, but I won't leave with any regrets.
"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's departure comes a few days after Mike Tindall, who stood in as captain at the World Cup when Lewis Moody was injured, was removed from the elite player squad and fined £25,000 after misleading the team management over a team night out in New Zealand.
There were also several other incidents of indiscipline during the tournament, but Johnson dismissed suggestions that his players had to take some of the blame for his departure.
"I haven't been let down. We toured together. Things get reported, but I don't think it was an accurate representation," he added.
"It made it difficult for us, but how much it affected things on the field, no one could answer that."
Johnson's departure drew mixed reaction from around the game.
Ex-England and Lions centre Jeremy Guscott, a former team-mate of Johnson's, told BBC Sport that the former Leicester player had "done the right thing", adding that "England's performance at the World Cup was abysmal and that was the end".
Former England captain Will Carling tweeted: "Sad for MJ. The man was an awesome player, incredible captain. One of THE greatest England players/servants."
The Rugby Football Union's director of elite rugby Rob Andrew, who has overseen three England managers during his time at Twickenham, said he would not be following Johnson in leaving his job.
"I'm absolutely not considering resigning. In terms of the department and the structure of the professional game - that's my role in this," he said.
"My job is to run the department, not just the playing side of things."
The position of Johnson's backroom staff of forwards coach John Wells, defence coach Mike Ford, scrum coach Graham Rowntree and attack coach Brian Smith is still not clear.
Johnson defended his coaching colleagues, saying he would not have continued in the role had they been removed by the RFU.
"That wouldn't have worked for anyone," he added. "They have handled themselves with a huge amount of integrity amid inaccurate speculation on their capabilities.
"International rugby is different from club rugby, from European rugby. They have a huge amount of knowledge and experience, it would be a waste for that to be lost from the union."
Former South Africa and Italy coach Nick Mallett was considered one of the front-runners to replace Johnson but ruled himself out on Wednesday, while New Zealand's 2011 World Cup-winning coach Graham Henry is thought to be in the frame.
Northampton coach Jim Mallinder, who has overseen England stars Chris Ashton, Ben Foden, Dylan Hartley and Courtney Lawes at Saints, has confirmed he would be interested in the role.
However, Jake White, who coached South Africa to World Cup success in 2007, has ruled himself out of the running.