The 15th was raised in September 1914, the 16th (which came to be known as McCrae's Battalion) in December 1914, and the 17th in February 1915, in Edinburgh. The 15th and 16th were assigned to the 34th Division and the 17th to the 35th Division, moved to France in early 1916, and first saw action at the first day on the Somme; all three spent the remainder of the war on the Western Front. The 15th and 16th were reduced to cadres in May 1918 and disbanded in August; the 17th was based in Belgium after the armistice, and provided internal security in France and Belgium in early 1919, before being reduced to a cadre in April and disbanded shortly afterward.