William Le Queux 
Invasion of 1910, with a full Account of the Siege of London 

What if German forces landed on the east coast of England and advanced on London while the British were struggling to mount a counter-attack? That’s premise of William Le Queux’s The Invasion of 1910, one of the most popular "invasion fiction" novels of all time. The novel revolves around Germany’s rising naval power and its threat to a weak Britain, unprepared for war politically, physically and psychologically. As the Germans occupy half of London, a junior Parliamentarian declares "Britain is not defeated." A newly formed Army liberates London, but the war is far from over. "The Invasion" was serialised in the Daily Mail in 1906 as tension of battleship construction threatened to erupt into military conflict between Germany and Britain. (Goodreads)