A crown dependency is territory that is self-governing under the authority/supervision of the British Crown meaning they have their own legal systems, legislative assemblies etc however are not a part of the UK. There are multiple Crown dependency’s in the modern day such as Jersey, Guernsey and the Isle of Man.

Jersey first became self-governing in 1204 after King John lost the Battle of Rouen against the French King Philippe-Auguste. At the time, the Channel islands were expected to have aligned themselves with France, however they decided to side with King John instead as it would grant them the right to be governed by their own laws, create the Jersey Royal Court [by allowing Jersey to choose their 12 best men to sit alongside the Bailiff] and a warden [which later became Governor] who was appointed by the King to organise the Island’s defence.