The 2/5th Battalion landed at Boulogne as part of the 3rd Highland Brigade in the Highland Division in May 1915 for service on the Western Front. The 2/6th Battalion, 2/7th Battalion and 2/8th Battalion all landed at Le Havre as part of the 197th Brigade in the 66th (2nd East Lancashire) Division in February 1917 also for service on the Western Front. The 3/5th Battalion landed at Le Havre as part of same brigade in March 1917 also for service on the Western Front. After the losses incurred during the German Spring Offensive in March 1918, the remains of the 2/7th Bn were reduced to a cadre and used to train newly arrived US Army units for trench warfare. The cadre then returned to England and was reconstituted as 24th Battalion. This was a training unit based at Cromer until the end of the war.