This pamphlet offers a condensed history of Europe between the fall of the Roman empire and the twelfth century. The author's profound anticlerical bias becomes apparent as he explores the influence of Christianity on a world in which order was maintained by the imposition of violence, and in which the general populace was kept in a state of ignorance and serfdom. He supports his conclusions with quotes from his own translations of documents of the period.
In the final sentence, McCabe sums up his view of the Dark Ages: "What claims to be the highest ethical religion in the world was followed after its general adoption by a general degradation of character to which you will find no parallel in the history of pagan civilization."