During the first two decades of the 20th century, a feeling of dread was pervasive in British culture: The British army’s initially shoddy performance during the Second Boer War (which lasted from 1899 to 1902) invited a whole host of theories as to why the British fighting man had so much difficulty in subduing South African irregular troops. One of the more popular explanations was that too much industrialization and urbanization were sapping British virility. John Frederick Maurice, a former Army officer who became a writer specializing in military issues and one of the era’s great alarmists, wrote that somewhere around 60 percent of all men presenting themselves for national service were physically unfit for duty. On the one hand, this could be called compensation. On the other, it was proper and fitting that the postwar spy narrative belonged to the Brits. After all, its origins lay in England’s angst-ridden buildup to World War I: Without the mostly manufactured anxieties of the pre-World War I popular press in Great Britain, the post-World War II generation would have lacked the right language and genre for the proper expression of British decline.

Maurice’s declarations caught the attention of the Inter-Departmental Committee on Physical Deterioration (who found his findings to be inflated) as well as the pamphleteer Elliott Mills, whose The Decline and Fall of the British Empire is excerpted in Robert Baden-Powell’s Scouting for Boys, the seminal text of what would become the widely influential Scout Movement. Besides the government and the Scouts, writers—especially pulp and thriller authors—also picked up on the widespread fear of British political and cultural decline.

The first text to elaborate on a hypothetical British collapse was George Tomkyns Chesney’s The Battle of Dorking: Reminiscences of a Volunteer. Published in 1871, Chesney’s novella deals with the successful invasion of Britain from a fictitious country that looks and acts a lot like the then-recently unified Germany. A former captain in the Royal Engineers, Chesney explicitly wrote it as an argument for increased military spending, especially in regards to technological innovation. It would go on to have a profound influence on both the spy and science fiction genres. (H.G. Wells’s popular War of the Worlds borrows a great deal from The Battle of Dorking.)

While he might have been the first, Chesney was far from the last British writer to use fiction as a platform for alarmist fantasies. The extremely popular turn-of-the-century author William Le Quex, who also lived an adventurous life as a diplomat and world traveler, followed in Chesney’s footsteps by writing two invasion novels of his own: The Great War in England in 1897, which singled out Russia and France as the two gravest dangers to British power, and The Invasion of 1910, which once again had a thinly veiled Germany as the culprit behind an invasion campaign that ultimately occupies half of London.