Calls for government action grew ever more intense, and in 1909 it was given as the reason for the secret foundation of the Secret Service Bureau, the forerunner of MI5 and MI6. Historians today debate whether this was in fact the real reason, but in any case the concerns raised in invasion literature came to define the early duties of the Bureau's Home Section. Vernon Kell, the section head, remained obsessed with the location of these saboteurs, focusing his operational plans both before and during the war on defeating the saboteurs imagined by Le Queux.