The 3rd and 4th Battalions fulfilled their role of training reinforcement drafts for the 1st and 2nd Bns. Both were stationed in Northern Ireland until April 1918 when they moved to Oswestry in the Welsh Borders and were amalgamated, at the same time absorbing the 12th (Reserve) Bn (originally formed from the depot companies of the 9th, 10th and 11th Bns).
