"Boulton Paul Defiant Mk I night-fighter of No. 264 Squadron RAF, silhouetted against the clouds during a low-level pass over its base at Biggin Hill, Kent, April 1941." Boulton Paul Defiant Mark I night-fighter of No. 264 Squadron RAF, silhouetted against the clouds during a low-level pass over its base at Biggin Hill, Kent.