The General Service Medal (1918 GSM) was instituted to recognise service in minor Army and Royal Air Force operations for which no separate medal was intended. Local forces, including police, qualified for many of the clasps, as could units of the Indian Army prior to 1947.
The GSM was equivalent to the 1915 Naval General Service Medal. Both these medals were replaced by the General Service Medal in 1962.
The 1918 GSM is a circular silver medal. The obverse shows the crowned effigy of the reigning monarch.
The reverse bears the standing winged figure of Victory in a Corinthian helmet and carrying a trident, bestowing a wreath on the emblems of the Army (the sword) and the RAF (the wings).
A bronze oak leaf emblem is worn on the ribbon of the medal to signify a mention in dispatches for a campaign for which the GSM was awarded.
Part of the resolution of the 1936-9 revolt was the imposition of an immigration quota for Jews wishing to enter Palestine. This was opposed by the Jewish settlers in Palestine, and in 1944 a guerrilla war was launched against the British forces there, principally by the Irgun and Lehi. While service in this conflict prior to May 1945 is counted as World War Two service, service between 27 September 1945 (the date a "state of emergency" was declared) and 30 June 1948 (when the last British troops departed) is acknowledged by this clasp to the GSM.