Derbyshire sack all-rounder Shiv Thakor after he was found guilty of two sexual exposure charges.
Sussex appoint ex-Australia bowler Jason Gillespie, who coached Yorkshire to two Championship titles, as their new head coach.
Essex appoint assistant coach and ex-Yorkshire and England all-rounder Anthony McGrath as their new head coach.
Kent all-rounder Will Gidman extends his contract with the Division Two club.
Audio & Video
New Essex head coach Anthony McGrath tells BBC Look East they must evolve, as people will no longer be surprised by the county champions.
Notifications, social media and more with BBC Sport
Follow your team with wicket alerts, sign up to news alerts or our newsletter and where to find us on social media.
How to get into Cricket
How to get into cricket - physical exertion with a chess-like element in matches which range from half an hour to five days.