The 38th (Irish) Infantry Brigade was created in early 1942 at the instigation of UK Prime Minister Winston Churchill.
Its creation was inspired by earlier fighting units with the same name: the Irish brigades that had been formed by exiled Irish soldiers fighting in the armies of France in the 17th and 18th centuries, and another participated in the American Civil War (1861-65). This latter formation was created by Thomas Meagher, who was convicted for his role in the failed Young Ireland rising of July 1848 and sentenced to transportation to Tasmania, escaped to the US and organised the Irish Brigade within the Union Army.
The creation of the Irish Brigade within the British Army was also a reminder of the time before the partition of the island of Ireland in 1922 when eight famous Irish regiments were mainly recruited from the young men of Ireland. Following partition, five of these regiments were dissolved. The survivors were the Royal Inniskilling Fusiliers (The Skins), the Royal Irish Fusiliers (The Faughs) and the Royal Ulster Rifles (formerly the Royal Irish Rifles).
The newly formed Irish Brigade comprised battalions from the three remaining Irish infantry regiments: the 1st Battalion of the Royal Irish Fusiliers; the 6th Battalion of the Royal Inniskilling Fusiliers and the 2nd Battalion of the London Irish Rifles, the territorial army counterpart of the Royal Ulster Rifles.