4th Royal Irish Dragoon Guards cap badge

The 4th Royal Irish Dragoon Guards was a cavalry regiment in the British Army, first raised in 1685 as the Earl of Arran's Regiment of Cuirassiers. It was renamed as the 4th (Royal Irish) Dragoon Guards in 1788 and service for two centuries, including the First World War, before being amalgamated with 7th Dragoon Guards (Princess Royal's), to form the 4th/7th Dragoon Guards in 1922.