The Royal Irish Rifles was a British Army Infantry Regiment. It dates back to the reign of King George 111. In 1793 the British Army raised 2 new Regiments to meet the commitmentd of the war with the French First Republic. In 1881 under the Childers Reforms these 2 regiments were amalgamated to form the Royal Irish Rifles,it saw service in the Second Boer War, Great War. In 1921 it was renamed the Royal Ulster Rifles. Quis Separabit = "Who shall seperate us" (Latin)
In 1968 under reforms of the army, was amalgamated with The Royal Inniskilling Fusiliers and the Royal Irish Fusiliers to form the Royal Irish Rangers.
More information on this Regiment can be found on Wikipedia under Royal Ulster Rifles
This Royal Irish Rifles Hat badge appears to be a Pewter type alloy with brass clip.
At top a Crown. Centre is harp shaped. Left side of harp has the figure of a siren her wings join to the right side of the harp which is a bar? adorned with raised decor. Bottom is a scroll with the lettering- Qius Separabit.
Inscriptions & markings
Harp -Siren on left, wings joining to the right side with raised decor
Scroll has - Quis Serarabit