Despite initially looking to replace the entire system after the Boer War, the British Short, Magazine, Lee Enfield really came into its own during the Great War, cementing itself as one of the most iconic weapons of the conflict.

Shortly after the turn of the 20th century, the British Royal Irish Constabulary adopted a new carbine for its constables, built from older MkI Lee Enfield and Lee Metford Carbines with some modifications. These would serve through the Easter Rising of 1916, as well as the subsequent Irish War of Independence that would see the end of British rule in most of Ireland, and the dissolution of the RIC itself in 1922.

As the Second World War loomed, a need to update the venerable Lee Enfield rifle in British service saw the design modernized into the new #4 Rifle, with a series of improvements on the same core principals.