This volume contains two imaginary tales of a, German invasion of England. The first, The Battle of Dorking, was written in 1871 by Sir George Tomkyns Chesny, and sparked great controversy when it was initially serialized anonymously in Blackwood's Magazine. It inflamed the English anxieties over the emergence of Germany as a great military power, and raised doubts about the preparedness of Britain for a possible war. In the story, German invaders conquer England because they are better trained, better equipped, and have a vast conscript army. In turn, the story is both a thinly-veiled call to action by Chesny, as well as a well-crafted work of fiction.
The second story in the volume, When William Came by Saki, is a bitter tale which imagines England under the rule of a German royalty now ensconced in Buckingham Palace. Written in 1913, it was published at a time when world war was inevitable--indeed, Saki would soon lose his life in the war on the continent.
Both books mark the course of the then-flourishing "future war" genre, showing the fascination for invention on the part of the authors, and their impassioned pleas to their readers patriotism. [via]