Partition of Ireland.

HM King George V receives the disbanded Irish Regiments' Colours at Windsor Castle, 12 June 1922.

Prior to the partition of Ireland on 3 May 1921, it had been ordered that all the Irish infantry regiments would be disbanded. However, this was later amended to permit the continuance of two Northern Ireland based regiments, each of two battalions.

On 12 June 1922, King George V received the Colours of The Royal Irish Regiment, The Connaught Rangers, The Prince of Wales’s Leinster Regiment, The Royal Munster Fusiliers and The Royal Dublin Fusiliers for safekeeping at Windsor Castle where they remain. The name of The Royal Irish Rifles had been changed on 1 January 1921, to The Royal Ulster Rifles, to bring it into line with The Royal Munster Fusiliers, The Leinster Regiment and The Connaught Rangers. In recognition of the number of battalions raised by The Royal Irish Rifles during the First World War the regiment was saved from disbandment.

The Royal Inniskilling Fusiliers was the senior of the northern regiments, whilst the King was Colonel-in-Chief of The Royal Irish Fusiliers; thus all three regiments had reason to hope that they would escape disbandment.

It was eventually decided that the two junior battalions should go - these were The 108th Regiment (2nd Battalion The Royal Inniskilling Fusiliers) and The 89th Regiment (2nd Battalion The Royal Irish Fusiliers). This led to the establishment of the Corps of Royal Inniskilling Fusiliers and Royal Irish Fusiliers with a common depot in Omagh.

This state of affairs continued until 1937, when, with the imminent outbreak of war, both second battalions were restored.