Calderwood's side clinched a European place on the final day
Jimmy Calderwood has left his post as Aberdeen manager, with the club saying it was "by mutual consent".
He departs Pittodrie along with assistant Jimmy Nicholl and coach Sandy Clark after five years with the Scottish Premier League club.
The announcement came only hours after the club clinched fourth spot - and a Europa Cup place - with a 2-1 win over Hibernian on the season's final day.
Calderwood told the club website: "The time is right for a new challenge."
He had refused to confirm his exit immediately after the win at Pittodrie that clinched a return to Europe on goal difference after Dundee United's 3-0 defeat by newly-crowned champions Rangers.
But the decision had already been agreed before kick-off, although Calderwood stressed that he did not have another job lined up should he leave.
"I have a contract for two years, but we have to talk to a few people and see what happens," he had said.
A couple of hours later, he was full of praise for the club despite the announcement of his departure.
"I love Aberdeen. I love the club and the city and I have thoroughly enjoyed my time here," he said.
The former Dunfermline boss arrived at Pittodrie in the summer of 2004, replacing Steve Paterson at the helm, and turned the fortunes of the club around almost immediately.
We left a club, Dunfermline, when they were in Europe and, outside the Old Firm, we have been the most consistent in the top six
Former Aberdeen manager Jimmy Calderwood
However, following this season's Scottish Cup exit at the hands of First Division Dunfermline, the AFC Trust wrote an open letter to director of football Willie Miller demanding Calderwood be sacked.
The former manager, though, insisted that such criticism had not left him disillusioned.
"I would like to thank the fans for their support as the vast majority have been fantastic," he said.
"I would also wish Aberdeen Football Club all the very best for the future and I depart knowing my successor will have a solid platform from which to move forward, including the return of European football next season."
Calderwood described as "wonderful" qualification for the new Europa Cup next season.
"We've got a wonderful record, Jimmy, Sandy and I," he said. "We left a club, Dunfermline, when they were in Europe and, outside the Old Firm, we have been the most consistent in the top six.
"People say that's not enough, but we've been in Europe three times."
Calderwood did admit that Aberdeen's record in cup competitions was his biggest regret.
He was also disappointed that two of the club's most experienced players - midfielders Scott Severin and Jamie Smith - would be leaving in the summer.
"If you look at the players we have lost in the last few years, we could have had a magnificent team," Calderwood added, alluding to the tight budget that has led to several players departing Pittodrie for more lucrative offers elsewhere.
Miller, who is also a previous manager of the club, thanked Calderwood and his team via the club website for the "substantial contribution they have made in stabilising things over the past five years, including of course qualification again for Europe".
"When they arrived, there was a massive rebuilding task required and subsequently we have seen the fruits of their efforts with regular top-six finishes in the league," he said.
"While the absence of a domestic trophy continues to be a source of frustration, the three of them can be proud of what they have achieved."
Speculation has already linked Motherwell manager Mark McGhee, a former Aberdeen player, with the vacancy.
However, McGhee told BBC Scotland that he had not been approached and that he did not have "any indication that Aberdeen are interested in me".
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