The British War Medal was instituted on 26 July 1919 for award to those
who had rendered service between 5 August 1914, the day following the
British declaration of war against the German Empire, and the armistice of
11 November 1918, both dates inclusive. Unlike the 1914 Star and the 1914–15
Star, the British War Medal could be awarded to all officers and men of
British and Imperial forces who had served for a prescribed period during
any stage of the war, or who had died on active service before the
completion of this period. Eligibility for the award of the medal was
subsequently extended to cover service in 1919 and 1920 in mine-clearing
at sea as well as participation in operations in North and South Russia, the
eastern Baltic region, Siberia, the Black Sea and the Caspian Sea.