sentences:  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.The Staffordshire Yeomanry, after a short period of training at Diss, Norfolk with the North Midland Mounted Brigade, was ordered to join the Egyptian Expeditionary Force in 1915.