Head coach Karl Krikken has left Derbyshire to pursue new opportunities as the club look to restructure their coaching set-up.
The 44-year-old, who in 2012 led the county to their first County Championship promotion - as Division Two winners - a year after taking over but immediately suffered relegation, enjoyed a 17-year playing career at the County Ground and in total spent 27 years at the club.
From 1987 to 2003 Krikken scored over 7,000 runs and totalled almost 800 dismissals as wicketkeeper.
He said: "I would like to thank the off-field staff, groundsmen, coaches, players and members for all their help and support during my time at Derbyshire.
“I have thoroughly enjoyed my time at the club, firstly as a player and then as a coach.
"As a player I was lucky enough to play with some magnificent cricketers that brought success to the county, winning a couple of one-day cups.
"In the last couple of years during my tenure as head coach, I have been immensely proud to lead a team of great lads to the first trophy for Derbyshire in 19 years and last year to our highest championship finish since 1996."
Chairman Chris Grant added: "It's sad that Karl's time at the club has come to an end and we thank him for his contribution to drafting the new elite player pathway, we respect his decision to seek opportunities elsewhere and we wish him all the very best for the future.
"Karl was a stalwart for our club as a wicketkeeper, his contribution as the first director of our academy was critical to our future, and who can forget the glory of promotion as Division Two champions under his stewardship?"