Chesterfield have appointed Paul Cook as their new manager on a two-and-a-half-year contract.
The 45-year-old has taken charge of the Spireites after the club secured his release from their League Two rivals Accrington following a day of negotiations.
Tommy Wright has been in temporary charge at the Proact Stadium since John Sheridan was sacked on 28 August.
Sheridan led the club to promotion in 2010/11 but they lasted only one season in League One and are currently 13th in League Two.
Wright and coach Mark Crossley will remain part of the backroom team under Cook.
Cook, who has previously managed Southport and Sligo Rovers, told Chesterfield's website: "I'm delighted to be the new Chesterfield manager.
"It's a fantastic club with a great infrastructure and I'm really looking forward to the challenge."
Chief executive Chris Turner said: "Paul did a fantastic job in Ireland and has done well with a very small budget at Accrington. He's very hungry to succeed and hopefully the change of direction will bring success to the club.
"I'd like to thank Tommy Wright and Mark Crossley, who have done excellent jobs in very difficult circumstances over the last couple of months. I'm delighted that they are staying."