The Battle of Britain 'officially begins'

10th July 194O: The day sees Luftwaffe attacks probing British air defences, as Churchill stresses any invasion can be met by the Navy - with 'Air support'

Many pilots had been in action for a considerable time before 10th July. Still from gun camera film shot by ‘Battle of Britain Ace’ Flight Lieutenant A G "Sailor" Malan, leader of 'A' Flight, No. 74 Squadron RAF, recording his first aerial victory, a Heinkel He 111 over Dunkirk at the end of May.

A flight of Hawker Hurricane Mk Is of No. 151 Squadron take off from North Weald, while beneath them, Hurricanes of No. 56 Squadron taxy to the northern end of the main runway, May 1940.

A range of sources refer to the Battle of Britain “officially starting” on the 10th July. Yet it was not at all apparent at the time that a new phase of the German aerial assault on Britain was beginning. Two RAF fighter pilots had been killed defending British airspace on the 9th July, and more before. A good case could be made that the massed Stuka attack on HMS Foylebank in Portland harbour on the 3rd July marked a step change in German tactics - although on that occasion, RAF Fighter Command were not involved in the action.

The 10th July marks the date of the battle for the purpose of the award of the Battle of Britain clasp, the commemorative medal awarded to aircrew who served during the period. It was sewn to the ribbon of the 1939/45 Star, the campaign medal for those who served in the war between 1939 and 1945.

A genuine Battle of Britain clasp issued to aircrew ( there are many copies in circulation). It was authorised for aircrew members of stipulated squadrons of Fighter Command who flew at least one operational sortie between 00.01 hrs 10th July and 23.59 hrs 31st Oct 1940.

The decision as to who was eligible for the award did not come until 1945 - and it was only intended for aircrew in specific RAF squadrons. It was not awarded to any members of the ground crew or operations staff who were also on the frontline, many of whom were killed or seriously injured in attacks on RAF airfields. Nor was it awarded to Royal Navy pilots who fought alongside the RAF in battles over Britain and the English Channel from Fleet Air Arm airfields. And it was not eligible to RAF Bomber Command aircrew, who were often referred to as participating in the battle at the time, including by Churchill. They had to campaign until 2013 for a ‘Bomber Command’ clasp.