Simon Grayson will end the longest run as Preston North End manager since the 1960s when he takes the Sunderland job.
Grayson, 47, took the Lilywhites job on February 18, 2013, succeeding Graham Westley in the Deepdale hotseat.
His initial task was to steady the ship after the turbulent Westley era.
A similar job faces him at Sunderland who have been without a manager for more than five weeks and are facing up to life in the Championship after relegation from the Premier League.
In his first few months at the Preston helm, he steered the club away from the threat of relegation.
The following season, North End reached the League One play-off semi-finals where they were beaten 4-2 on aggregate by Rotherham.
In the 2014/15 campaign, Grayson guided PNE to promotion via the play-offs, with them beating Swindon 4-0 at Wembley.
They had blown automatic promotion on the last day of the season but bounced back to go up through the end-of-season knockout.
North End were the fourth club he had guided to promotion from League One after doing so at Blackpool, Leeds United and Huddersfield Town.
Under Grayson, PNE finished 11th in their first season back in the Championship, recovering from a shaky start to consolidate.
Last season, they ended in the same position with the same number of points as in 2015/16 after at one stage being on the fringes of the play-off race.
To mark his fourth anniversary in charge in February, North End supporters wore Grayson masks for the away game at Wigan Athletic.
Grayson had a 44.3% win rate during his four years and four months at Deepdale.
North End announced on Thursday morning that they had granted Sunderland permission to speak with Grayson, the Black Cats having agreed a compensation figure which was written into his contract.
First-team coach Steve Thompson oversaw the start of pre-season training at Springfields.