1st of April 1918
Over the entrenched battlefields of France and Belgium, the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS) were heavily involved in the war. But also competing among each other for aircraft as aircraft were in high demand, but short in supply. Following a report in 1917 from Jan Smuts (a South African member of the British Imperial War Cabinet) after the German strategic bombing of Britain, both services were amalgamated into the Royal Air Force (RAF) on the 1st of April, 1918. And in doing so became the first independent air force, not as a branch of the army of navy, but an independent military force. And at the time also the largest air force in the world.
The motto of the Royal Air Force on their badge "Per ardua ad astra" which means "through adversity to the stars" or "through struggle to the stars". Not only the official motto of the Royal Air Force, but also of other Commonwealth air forces such as the Royal Australian Air Force, Royal Canadian Air Force and Royal New Zealand Air Force,