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The 1939–1945 Star was awarded for operational service between 3 September 1939 and 2 September 1945, and thus covered the full duration of the Second World War. Two Clasps were instituted, with few Australian servicemen being eligible for these clasps unless they flew fighter aircraft during the Battle of Britain, or were Bomber Command crew on operational sorties.
The basic requirement was for 180 days in an operational unit, or in the case of air crew 60 days service in an operational unit with participation in at least one sortie. Merchant Navy personnel had to complete 180 days service with at least one voyage passing through an operational area. Any award of a Mention in Despatches, regardless of war service, automatically qualified the awardee to the 1939-45 Star.
The set of nine campaign stars was designed by the Royal Mint engravers. The stars all have a ring suspender which passes through an eyelet formed above the uppermost point of the star. They are six–pointed stars, struck in yellow copper zinc alloy to fit into a 44 millimetres diameter circle, with a maximum width of 38 millimetres and 50 millimetres high from the bottom point of the star to the top of the eyelet.
While the reverse was plain, the obverse has a central design of the Royal Cypher GRI VI. A circlet surrounds the cypher, inscribed THE 1939-45 STAR and is its top is covered by a crown.
The recipient's name was impressed on the reverse of the stars awarded to only three of the many countries to whom it was awarded - Indians, South Africans and, after a campaign led by veteran organisations, to Australians.
Content has come from a combination of Wikipedia and the Australian War Memorial websites.