Although there were unsatisfactory aspects in the manner of their sudden departure, there’s no doubt that City and County - not only Lincoln City Football Club - owe a huge vote of thanks to these hard-working soccer brothers.
When they arrived from Essex for their first professional managerial jobs in June 2016, City had completed their fifth season in the non-league Conference, finishing as usual, in mid table.
The area had not known a truly successful club since the 1970s and 80s. The club was moribund, taken for granted, and just hanging on financially. “Waiting for a chink” was how Bob Dorrian, then Chairman, put it. Gates were often below 3000.
Enter the Cowley Bros and their major shakeup. They brought in bright new players, and re-enthused existing ones. They employed a shoal of new ideas, sports science, and statistical analysis to deliver a winning team.
One night’s TV coverage in January 2017 did more good for the city than tourism chiefs had achieved in a decade.
The non-league Imps had battled their way to the third round of the FA Cup and earned an away draw at Ipswich Town of the Championship. Against the odds, the Imps deservedly drew 2-2 and brought Ipswich to Sincil Bank for the replay.
BBC TV1 had FA Cup rights and decided to cover it live. It was the pull out and tilt down from the floodlit Cathedral to the soccer stadium - a unique view in British football - that so enthused the BBC commentator Gabby Rosen.
Millions saw it and clocked what an interesting city Lincoln is. Positive vibrations were endorsed when Nathan Arnold scored the injury time winner that put City in the next round. Had the game gone to extra time the BBC would have had to put back News at Ten!
Fantastic wins against Brighton, also of the Championship, and in particular away at Premier League Burnley took Lincoln further in the FA Cup than any non-league team since 1914.
A sixth round tie at Arsenal in the FA Cup Quarter Final was of course a step too far for the team but it meant that the club could invest its cup earnings in a new training ground and top notch gym and physio facilities.
Promotion back into the Football League came a few weeks later, followed by a play-off position in 2018 - a season that included the club's first ever trip to Wembley where they lifted the Checkatrade Trophy. And then the Division Two championship was secured in 2019.
The Cowley Bros brought about the biggest revival of any small town club and, outside the stadium, there were significant economic aspects.
When attendances multiply by 3 to 4 times, its brilliant for local businesses. Pubs, breweries, restaurants, takeaways, hotels, taxi companies and many others benefited.
Even the Commissionaire at Lincoln Theatre Royal told me: “People coming in here have told us they have come to Lincoln for the weekend because they had heard about it through the football.”
Although many fans are heartbroken as the brothers take their skills to Huddersfield Town, we can only say good luck and thank you.