Portsmouth have appointed Chesterfield boss Paul Cook as their new manager.
Cook takes charge of Pompey following the dismissal of former boss Andy Awford in April.
Cook, 48, was in the dugout as the Spireites were knocked out of the League One play-offs following a 3-0 defeat at Preston on Sunday.
"I'd like to thank the staff in all departments of the club for everything they have done during my time at the club," said Cook.
"Most importantly, I'd also like to thank the players, who have been fantastic, both on and off the pitch. Finally, thanks to the fans for their superb support."
Portsmouth said in a statement that talks were ongoing with Cook's assistant Leam Richardson about joining the coaching team at Fratton Park.
Speaking to BBC Radio Solent, chief executive Mark Catlin said: "Paul was a unanimous choice of the board. He's had great success in League One and Two, and plays a good brand of football.
"The compensation we've paid for Paul is relatively small in terms of the overall budget. The fans deserve the best and we feel we've gone out and got the best in Paul.
"He has already decided which players he'll be keeping. He'll be letting them know as soon as possible."
|Managers since winning the FA Cup in 2008|
|Harry Redknapp||October 2008|
|Tony Adams||October 2008 - February 2009|
|Paul Hart||February 2009 - November 2009|
|Avram Grant||November 2009 - May 2010|
|Steve Cotterill||June 2010 - October 2011|
|Michael Appleton||November 2011 - November 2012|
|Guy Whittingham||November 2012 - November 2013|
|Richie Barker||December 2013 - March 2014|
|Andy Awford||March 2014 - April 2015|
Cook had been in charge of Chesterfield since October 2012.
He guided them to last season's League Two title and their good form continued this term with a sixth-placed finish.
The former Wigan, Wolves and Burnley midfielder had previously managed Southport, Sligo Rovers in Ireland and Accrington Stanley.
Chesterfield chief executive Chris Turner said they hoped to appoint a replacement as quickly as possible.
"I could not have wished for a better working relationship than the one I have enjoyed with Paul over the last two-and-a-half-years and there is nobody more disappointed than me to see him leave," added Turner.
"We will be looking to appoint Paul's successor as soon as possible and the incoming manager will be in the enviable position of inheriting a strong squad."