The 10th (Service) Battalion landed at Boulogne-sur Mer as part of the 27th Brigade in the 9th (Scottish) Division in May 1915 for service on the Western Front. The 11th (Service) Battalion landed at Boulogne-sur-Mer as part of the 45th Brigade in the 15th (Scottish) Division in July 1915 for service on the Western Front. The 12th (Service) Battalion landed at Boulogne-sur-Mer as part of the 77th Brigade in the 26th Division in September 1915 but moved to Salonika in November 1915. The 14th (Service) Battalion landed at Le Havre as part of the 120th Brigade in the 40th Division in June 1916 for service on the Western Front.