According to contemporary newspaper reports, thousands of people saw mysterious airships flying over Britain between March and May 1909, and again between October 1912 and April 1913. There were at least fifty separate reported sightings in the former period and more than eighty in the latter. As the state of British aviation was insufficient to account for these sightings, the prevailing (although by no means uncontested) theory was that German airships were conducting secret reconnaissance and practice bombing missions over British soil, in preparation for the invasion which many people feared would one day come. These Zeppelins — gigantic lighter-than-air craft as long as dreadnoughts — outperformed contemporary aeroplanes in many respects and held the potential to become a revolutionary war-winning weapon. In a campaign reminiscent of the contemporary naval panics, the airship scares were used by Conservatives as a timely reminder that Britain’s perceived shortcomings in aerial defence needed to be addressed before war came. But in fact, for all but a tiny minority of mystery airship sightings the possibility of German involvement can be ruled out. This then raises the intriguing question of why people thought that they saw Zeppelins where there were none.