The Polish Squadrons saved Britain.
They contributed. The majority were British natives.
"The RAF recognises 2440 British and 510 overseas pilots who flew at least one authorised operational sortie with an eligible unit of the Royal Air Force or Fleet Air Arm during the period 10 July to 31 October 1940. This group includes 139 Poles, 98 New Zealanders, 86 Canadians, 84 Czechoslovakians, 29 Belgians, 21 Australians, 20 South Africans, 13 French, 10 Irish, 7 Americans, a Jamaican, a Palestine Jew and a Southern Rhodesian."