Badge of the Royal Air Force
The badge was based on a design by a tailor at Gieves Ltd of Savile Row. It was first used in August 1918 and the original circlet showed a garter and buckle. The present plain circlet dates from 26 January 1923 when the badge was registered at the College of Arms and, it being noted that the garter and buckle were heraldically incorrect, a substitution was made.
In heraldic terms it is: "In front of a circle inscribed with the motto Per Ardua Ad Astra and ensigned by the Imperial Crown an eagle volant and affronty Head lowered and to the sinister." Although there have been debates among airmen over the years whether the bird was originally meant to be an albatross or an eagle, the consensus is that it was always an eagle. 
The badge is depicted on the iron gates at the ceremonial entrance to the Royal Air Force College Cranwell; at the entrance to the Air Forces Memorial in Surrey; and on the Polish War Memorial in London.
Other air forces
Other Commonwealth air forces have adopted badges which are based on the RAF badge. Several are shown below:
- Cranwell Heraldry Part One: The Royal Air Force Badge – The Heraldry Society, September 2005
- Air Ministry Orders A.666/49, 15 September 1949
- It’s an albatross, it’s an eagle … it’s an eagle[dead link]