The Battleship Derby is one of the newer Dunkirk class battleships constructed at Southampton Shipyards for the Bretonian Armed Forces.
Originally tasked with protecting the northern frontier from hostile Kusari forces, the Derby was withdrawn to Leeds orbit following the fall of Glasgow Outpost and Stokes Mining Station to Kusari forces in 816.
The ship sustained some damage to an assault by Salazar Kithe's Immortal Hunter. However, since repairs were completed its firepower and armour are among the strongest of any capital ship in Bretonia, if not Sirius.
The Derby is the flag-ship of the 7th Fleet, under the temporary command of Lord Commodore Roger Bretram Brinkley, CC - one of Bretonia's longest-serving officers who returned to serve with his old regiment in the wake of the Kusari invasion.