Nigel Adkins’ sacking by Reading means Chris Powell is now the 72nd longest serving manager in the Premier and Football League – even though he was only appointed on September 3.
The Town boss is the 15th longest serving in the Championship.
Since Powell’s September 3 appointment to succeed Mark Robins, eight second-tier clubs have made changes.
They include Saturday’s visitors Birmingham City, who installed Gary Rowett in succession to former Town manager Lee Clark, who has himself replaced Jose Riga at Blackpool.
Riga, of course, took over from Powell as Charlton Athletic team chief last season.
The other new Championship managers are Neil Lennon at Bolton Wanderers, Russell Slade at Cardiff City, Kit Symons at Fulham, Neil Redfearn at Leeds United, Slavisa Jokanovic at Watford and Malky Mackay at Wigan Athletic.
The Championship’s longest serving manager is Rotherham United’s Steve Evans, appointed in April 2012.
The longest serving in the country in Arsenal’s Arsene Wenger, at 18 seasons, followed by former Town loan player Paul Tisdale, who has been at League II Exeter City since June 2006.
The departure of Adkins in the wake of Saturday’s 6-1 defeat at Birmingham means Reading are likely to have a new man at the helm by the time they visit Town in the third round of the FA Cup on January 3.
Former West Bromwich Albion boss and ex-Newcastle United, Birmingham and Norwich City manager Chris Hughton has already been linked.
But ex-Town loan player Brian McDermott has ruled himself out of a second stint at the Berkshire club, having recently taken up a scouting role at Arsenal.
Former Scunthorpe United and Southampton manager Adkins had 20 months in charge at Reading, who are 16th in the table and host Watford on Saturday.
Adkins took charge of Reading two months after being sacked by Southampton, having led the Saints from League I to the Premier League in successive seasons.
He was unable to prevent the Royals from being relegated from the top flight.
They finished seventh in the Championship last season and were only denied a play-off place by Leonardo Ulloa’s late winner for Brighton at Nottingham Forest.
Assistant manager Andy Crosby and coach Dean Wilkins have also left the club.
Reading captain Jem Karacan tweeted: “On behalf of the players I want to thank gaffer, Cros and Deano for everything they did here.
“They couldn’t have worked any harder.”