Sean O'Driscoll has been appointed as the new manager of Nottingham Forest on a three-year deal.
The Championship club had been looking for a new coach after Steve Cotterill was sacked by new owners the Al-Hasawi family last week.
O'Driscoll has left Crawley Town without taking charge of a first-team game after he became boss of the League One side in May.
"We interviewed many well-known and high profile figures but none of them impressed us as much as Sean O'Driscoll," majority shareholder Fawaz Al Hasawi told Forest's official website.
"Sean's passion for Nottingham Forest, knowledge of the game and the Championship in particular, plus his work ethic, shone through in our conversations.
"He is hugely respected, not only by members of our current squad and staff at the club for his work in helping transform our fortunes last season, but also within the wider football community."
The 55-year-old had been part of the coaching team at Forest under Cotterill before he took the job at Crawley.
Despite the departure, Crawley have revealed that they were not prepared to stand in the way of O'Driscoll's plans.
"The club is extremely disappointed to be losing Sean so soon after he came to Crawley Town," chief executive Alan Williams told the club's official website.
"But our policy has never been to stand in the way of any employee who feels they would prefer to pursue a role at a different club and following lengthy and intensive negotiations we have been able to agree compensation with Nottingham Forest which will include a friendly before the 2013-14 season at the City Ground.
"We would like to thank Sean for his efforts during his time at the club and we wish him all the best for the future."
O'Driscoll has also had spells in charge of Bournemouth and Doncaster Rovers after he began his managerial career in 2000.