The 1/8th mobilised at Haddington in August 1914, and arrived in France in November – the first Scottish territorial unit to arrive in France – with the 7th Division, though they did not see action until the Battle of Neuve Chapelle. After the Second Battle of Ypres, in August 1915, they were transferred to the 51st (Highland) Division as the divisional pioneers, and disbanded in March 1919 at Haddington The 1/9th mobilised at Edinburgh in August 1914, and moved to France in February 1915 with the 27th Division; when this moved to Salonika in November they remained in France, transferring to the 5th Division, and then to Third Army reserve. They were assigned to the 51st (Highland) Division in March 1916, with whom they fought for two years, then to the 61st (2nd South Midland) Division and 15th (Scottish) Division in 1918.