Who is the EFL's longest serving manger?

I met Jim Bentley when we last played them at Priestfield .A warm a friendly guy .Who really loved our stadium .Rated a few of our players at the time but not Fuller so I would be really shocked if he ended up at Morecambe .Shows how crazy football management is that the team that came nearest to dropping out of the league have the longest serving manager .Still Jim has done a amazing job keeping them in the league with little or no money .A world away from Wenger and co .