Imperial War Service:

The Territorial Force (TF) was created on 1 April 1908 from the old Volunteers and Yeomanry and was a pure home defence force. In 1910/11 the Government polled units to see if there were members willing to serve overseas in time of crisis. Individual members who accepted this commitment joined the 'Imperial Service Section' and were entitled to wear the silver 'Imperial Service' badge (instituted in 1912) on the right breast. There are no records to who the badge was issued to. The Imperial Service badge is worth between 12 to 15 and part of my collection of medals and badges. Shown here larger than life, the actual size is 10mm x 43mm.  

If a unit had 90% of its establishment volunteer, the soubriquet' Imperial Service' was conferred. Prior to the outbreak of WW1 only three Territorial Force infantry battalions met this challenge, the first was the  7th (Imperial Service) Battalion, the Duke of Cambridge's Own (Middlesex Regiment) followed by the  8th (Imperial Service) Battalion, the Duke of Cambridge's Own (Middlesex Regiment) and the 6th (Imperial Service) Battalion, the East Surrey Regiment.