Australians in Fighter Command.
Most Australian WW2 fighter pilots flew as RAF Officers in RAF squadrons during the Battle of Britain with the pilots involved in intense fighting action during the German invasion of France and during the Battle of Britain.
These pilots were savvy and experienced fighter pilots – but most perished in the the ferocious fighting in the battle, such as FO L.R. Clisby DFC, (RAF Hurricanes - KIA France 15 May) who is credited with 17 and one half victories in France and Flight Lieutenant P.C. Hughes DFC, (234 Squadron (Spitfires) (Middle Wallop).
Hughes was the top Australian 'ace' of the Battle of Britain with 14 individual and 4 shared victories, and one of fourteen Australian fighter pilots killed during the battle.
He was later described as "the inspiration and driving force behind No. 234 Squadron RAF". Hughes is credited with seventeen confirmed victories—fourteen solo and three shared, placing him as one of the top ten Allied Battle of Britain aces. It also ranks him among the three highest-scoring Australians of World War II, after Clive Caldwell with thirty victories and Adrian Goldsmith with seventeen victories.
Other Australians who served with great distinction as members of the RAF were Air Commodore 'Hughie' Edwards VC and Air Vice Marshal D. Bennett, the founder of the famous Bomber Command 'Pathfinder' Force.
Later in the war 452, 453, 457 and *456 squadrons (*Mosquitoes – Night Fighter Squadron) and RAAF No. 10 Coastal Command were right in the thick of it in England and Europe from late 1941- 42 onwards.
Here's a great background information link on 'Australia's Few and the Battle of Britain' - from Aussie author - Kristen Alexander - from the Battle of Britain Memorial