It consisted of the old Ulster Volunteer Force, which had originally been raised to resist the imposition of Home Rule.

In early 1918, on re-organisation, 107 Brigade consisted of the 1st and 2nd (Regular) and the 15th (Service) Battalions of the Royal Irish Rifles.

The Territorial Army throughout the United Kingdom was reconstituted in 1947 and, for the first time, there was a full scale TA organisation of all Arms in Ulster.

Authority was given by the War Office for the formation on 1 January 1947 of 107 (Ulster) Independent Infantry Brigade (TA).

This was part of the complete reorganisation, announced in the 1966 Defence White Paper, which abolished the former regimental and divisional structure of the Territorial Army.