David Moyes has resigned as Sunderland manager following their relegation from the Premier League, the club announced on Monday.
The 54-year-old Scot succeeded Sam Allardyce last July and oversaw a desperate season that saw Sunderland finish 16 points adrift of safety at the foot of the table.
"I would like to thank (chairman) Ellis Short and the board for giving me the opportunity to manage Sunderland and the fans for always being so passionately supportive of their club," Moyes said in a statement.
"I wish the players and my successor well in their efforts towards promotion back to the Premier League."
Sunderland's relegation to the Championship after 10 years in the top flight was confirmed following a 1-0 home defeat by Bournemouth last month.
Moyes informed Sunderland officials of his decision to leave at a meeting in London on Monday.
His departure completes a sorry few weeks for the former Everton manager, who has been charged by the Football Association after jokily threatening to "slap" a female reporter.
It is his third successive short-lived stint at a club, following previous disappointments at Manchester United, where he lasted just 10 months, and Real Sociedad.
"I pursued the services of David Moyes for a considerable period prior to his appointment last summer, which makes the announcement of his departure difficult for everyone concerned," said Sunderland chairman Ellis Short.
"Having worked tirelessly throughout the campaign to avoid relegation from the Premier League, David has chosen to leave the club without compensation, which is testament to his character.
"In the days ahead we will take some time for reflection and then focus on recruitment and pre-season as we prepare for our Championship campaign. We wish David well in the future."
Moyes was dissatisfied with Sunderland's close-season transfer dealings and set the tone for their campaign early in the season when he said he was preparing for a relegation battle.
Sunderland sank into the bottom three in September and did not move off the foot of the table from January onwards, finishing the campaign with only six wins to their name.
An incident involving Moyes and BBC radio reporter Vicki Sparks occurred after a 0-0 draw against Burnley on March 18, but only came to light last month.
After taking exception to a question, Moyes waited until the interview had ended before telling Sparks: "It was getting a wee bit naughty at the end there, so just watch yourself.
"You still might get a slap even though you're a woman. Careful the next time you come in."
He subsequently apologised, but was charged by the FA on April 26.