Royal Militia of the Island of Jersey

Formed in 1337, the Royal Militia of the Island of Jersey can claim to be the oldest sub-unit of the British Army, although, because it is not a regiment, and was disbanded for decades in the late 20th century, it is not the most senior. == History == A militia force was organised in accordance with the order on 24 July 1203 of King John to provide a "sufficiency of men and money to defend the Island from the enemy".

Source: Wikipedia — Royal Militia of the Island of Jersey (CC BY-SA 4.0)