In accordance with the Territorial and Reserve Forces Act 1907 (7 Edw.7, c.9) which brought the Territorial Force into being, the TF was intended to be a home defence force for service during wartime and members could not be compelled to serve outside the country.

However, on the outbreak of war on 4 August 1914, many members volunteered for Imperial Service.

Therefore, TF units were split in August and September 1914 into 1st Line (liable for overseas service) and 2nd Line (home service for those unable or unwilling to serve overseas) units.

[3] Further reorganization in October and November 1916 saw the brigade redesignated as 7th Cyclist Brigade in November, now in the Bridlington area.

2/1st Yorkshire Hussars was stationed at Fermoy, County Cork and Fethard, County Tipperary[7] the 2/1st Yorkshire Dragoons at Fermoy,[7] and the 2/1st East Riding at Bandon, County Cork and Fermoy.