 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.Later, a 3rd Line was formed to act as a reserve, providing trained replacements for the 1st and 2nd Line regiments.With the outbreak of the First World War in 1914, the regiment mobilised in the North Midland Mounted Brigade and moved to France in November joining the 3rd Cavalry Division.