The biggest summer in English cricket history gets underway on Friday as the county season starts in earnest.
Surrey will be hoping to defend the crown they won in style last year, while Alastair Cook begins his post-international career at Essex.
Sportsmail take a look at the runners and riders and pick out some players to watch this summer...
Surrey will be defending their 2018 County Championship crown at the Oval this season
Derbyshire
Head of cricket: Dave Houghton
Captain: Billy Godleman
Overseas players: Logan van Beek (New Zealand), Kane Richardson (Australia, Twenty20)
IN: Tom Lace (Middlesex, season loan), Mark Watt (Scotland, season loan)
OUT: Ben Slater (Nottinghamshire), Will Davis (Leicestershire), Callum Brodrick (released), Hardus Viljoen (released), Gary Wilson (Ireland central contract)
One to watch: Matt Critchley. A big season for the all-rounder, who scored in excess of 700 Championship runs and took 32 wickets with his leg-spin in 2018.
Durham
Lead performance coach: James Franklin
Captain: Cameron Bancroft
Overseas players: Bancroft (Australia), D'Arcy Short (Australia, Twenty20)
IN: Alex Lees (Yorkshire), Ben Raine (Leicestershire), Jack Burnham (back from ECB ban), Ned Eckersley (Leicestershire)
OUT: Paul Collingwood (retired), Barry McCarthy (Ireland central contract), Ryan Davies (released)
One to watch: Jack Burnham. A second chance post-drugs suspension for a young player to fulfil the talent that saw him break the England' record for runs at an Under-19 World Cup three years ago.
Essex
Head coach: Anthony McGrath
Captain: Ryan ten Doeschate
Overseas players: Peter Siddle (Australia), Adam Zampa (Australia, Twenty20)
IN: Cameron Delport (Leicestershire)
OUT: James Foster (retired), Ashar Zaidi, Callum Taylor, Matt Dixon (all released)
One to watch: Sir Alastair Cook. Not a lot to prove but a lot to give, the former England captain starts a three-year commitment to the county game.
Alastair Cook returns to the fold at Essex after calling time on his international career
Glamorgan
Interim head coach: Matthew Maynard
Captain: Chris Cooke
Overseas player: Shaun Marsh (Australia)
IN: Billy Root (Nottinghamshire), Charlie Hemphrey (Queensland)
OUT: Aneurin Donald (Hampshire)
One to watch: Charlie Hemphrey. Englishman, Sheffield Shield winner, and now - at the belated age of 29 - county cricketer.
Gloucestershire
Head coach: Richard Dawson
Captain: Chris Dent
Overseas players: Dan Worrall (Australia), Michael Klinger (Australia, Twenty20)
IN: Stuart Whittingham (Sussex)
OUT: Liam Norwell and Craig Miles (both Warwickshire), Kieran Noema-Barnett (released)
One to watch: Matt Taylor. Younger brother of Jack, the left-arm fast bowler has a chance to step up as attack leader across all formats.
Hampshire
Head coach: Adrian Birrell
Captain: James Vince
Overseas player: Aiden Markram (South Africa)
IN: Donald (Glamorgan), Keith Barker (Warwickshire), James Fuller (Middlesex)
OUT: Jimmy Adams, Sean Ervine (both retired), Calvin Dickinson, Asher Hart, Reece Topley, Chris Sole (all released)
One to watch: Vince. Will open the batting, at the behest of England selector Ed Smith, as the scrimmage for Ashes places takes shape.
Kent
Head coach: Matt Walker
Captain: Sam Billings (Heino Kuhn will deputise while Billings at IPL)
Overseas players: Matthew Renshaw (Australia), Adam Milne (New Zealand, T20), Mohammad Nabi (Afghanistan, T20)
IN: Matt Milnes (Nottinghamshire), Fred Klaassen (Netherlands)
OUT: Will Gidman, James Tredwell, Matt Hunn (all retired)
One to watch: Grant Stewart. Australian-raised player who has impressed with both bat and ball in short first-class career to date.
Lancashire
Head coach: Glen Chapple
Captain: Dane Vilas
Overseas players: Joe Burns (Australia), James Faulkner (Australia, T20), Glenn Maxwell (Australia, CC/T20 split)
IN: Richard Gleeson (Northamptonshire)
OUT: Jordan Clark (Surrey), Arron Lilley (Leicestershire), Simon Kerrigan, Karl Brown (both released)
One to watch: Haseeb Hameed. Once destined to reign at the top level, the three-cap Test opening batsman enters the final year of his contract, having averaged single figures in last year's Championship.
Leicestershire
Head coach: Paul Nixon
Captain: Paul Horton
Overseas player: Mohammad Abbas (Pakistan)
IN: Davis (Derbyshire), Lilley (Lancashire), Chris Wright (Warwickshire), Hasan Azad (ex-Loughborough University)
OUT: Raine (Durham), Delport (Essex), Zak Chappell (Nottinghamshire), Michael Carberry, Eckersley, Richard Jones, Mark Pettini, Rob Sayer, Tom Wells
One to watch: Tom Taylor. Former Derbyshire seamer will get opportunities following the departures of Raine and Chappell.
Middlesex
Head coach: Stuart Law
Captain: Dawid Malan
Overseas players: AB de Villiers (South Africa, T20), Mujeeb Ur Rahman (Afghanistan, T20)
IN: None
OUT: Fuller (Hampshire), Nick Compton (retired), Ravi Patel (released)
One to watch: Toby Roland-Jones. The England international is fit again after missing 18 months of cricket through injury.
Northamptonshire
Head coach: David Ripley
Captain: Alex Wakely
Overseas players: Jason Holder (West Indies, April), Temba Bavuma (South Africa, May 14-July 17), Faheem Ashraf
