(ROC) was formed as a defence warning organisation with civilians trained in aircraft recognition and operated primarily as such between 1925 and 1957. Aircraft recognition was first developed between the First and Second World wars when aerial warfare was first recognised as a future threat, after 208 Zeppelin and 435 aircraft raids over London during the First World War. In 1917 Germany had started using fixed-wing bombers, and the number of airship raids diminished rapidly.

To answer this new threat, Major General Edward Bailey Ashmore,