The 45th Battalion departed Alexandria on 2 June 1916, arriving at Marseilles on 8 June. In August, the battalion was committed to the fighting at Pozières, losing 448 men on its first tour. For his leadership at Pozières, Herring was mentioned in dispatches and awarded the Distinguished Service Order (DSO). At Messines in June 1917, the battalion lost 568 men in pillbox fighting on the Oosttaverne Line. Herring, who had ordered repeated attacks on pillboxes that his men could not capture, was again mentioned in dispatches. On 24 September 1917 he became a brevet major in the AMF.