end of the war. The 1939–1945 Star was awarded for operational service between 3 September 1939 and 2 September 1945, and was the only campaign star that covered the full duration of the Second World War. Two clasps were instituted to be worn on the medal ribbon, along with rosettes to be worn on the ribbon bar of the medal to denote the award of a clasp: The Battle of Britain Clasp was instituted in 1945 for award to air crew members on fighter aircraft who took part in the Battle of Britain from 10 July to 31 October 1940. A total of 2,936 airmen qualified for the clasp. A silver-gilt rosette, worn on the ribbon bar, denotes the award of this clasp. The Bomber Command Clasp was belatedly instituted on 26 February 2013, for award to air crew members on aircraft who participated in at least one operational sortie in a Royal Air Force Bomber Command operational unit between 3 September 1939 and 8 May 1945 inclusive. A silver rosette worn on the ribbon bar denotes the award of this clasp. Award criteria Broad criteria The 1939–1945 Star was awarded for specified periods of operational service overseas between 3 September 1939 and either 8 May 1945 in Europe or 2 September 1945 in the Far East theatre. The broad criteria were 180 days of service between these dates, with more specific criteria depending on service arm. Naval personnel qualified after 180 days afloat between certain specified dates in areas of operations as laid out in the regulations. Army personnel had to complete 180 days of service in an operational command. Airborne troops qualified if they had participated in any airborne operations and had completed 60 days of service in a fully operational unit. Air Force air crew qualified after 60 days of service in an operational unit, including at least one operational sortie. The 1939–1945 Star was also awarded to crews of transport aircraft who flew over certain specified routes. Air crew of fighter aircraft engaged in the Battle of Britain were also awarded the Battle of Britain Clasp, while air crew of bomber aircraft who participated in at least one operational sortie in a Bomber Command operational unit were awarded the Bomber Command Clasp in 2013. Ground crew and other Air force personnel qualified upon completion of 180 days of service in an area of operational army command.