The Royal Irish Regiment (27th (Inniskilling), 83rd, 87th and The Ulster Defence Regiment) (R IRISH) is an infantry regiment of the British Army. The regiment was founded in 1992 through the amalgamation of the Royal Irish Rangers and the Ulster Defence Regiment. Their oldest predecessor, the 27th Regiment of Foot, was first raised in June 1689 to fight in the Williamite War in Ireland. Other notable regiments in their lineage include the Royal Inniskilling Fusiliers, Royal Irish Rifles and the Royal Irish Fusiliers (Princess Victoria's).