Shortly after the outbreak of World War One, Charles Masterman was appointed by Prime Minister Asquith to oversee a covert literary propaganda campaign in support of the British war effort. Although William Le Queux had been one of the most prominent British anti-German writers during the prewar years, he was not recruited for this governmental endeavour that included many of the nation's best-known writers. Nonetheless, he continued on his own to publish anti-German propaganda throughout the war. These two articles assess Le Queux's national security-oriented writings within that broader context, and they offer a methodology for gauging the potential efficacy of such texts based on recent developments in the field of risk-perception studies. Part One provides a historical and methodological foundation for both articles and assesses a number of Le Queux's pre-1914 works. Part Two (published in Part II of this issue) examines Le Queux's career and writings from 1914 through to his death in 1927.