What if the Allies hadn't won the Second World War? What if the conquering Japanese and German armies divided up the United States?
In The Man in the High Castle, Dick explores the chain of events that would cause such a state of affairs, and what life would be like if the Allies has not won. The story primarily focuses on very ordinary people living their daily lives in this society, though many of them find themselves unwittingly embroiled in events that shape the fate of nations.
As in so many of Dick's novels, The Man in the High Castle focuses on the idea of authenticity. How can we tell what is real? How do we know what really happened in history? How do we act authentically ourselves in a world that often seems to demand we act disingenuously? Moreover, can things, people, and ideas that originated as fakes or imitations ever take on a true life of their own?
During the writing of the novel, Dick used the I Ching (an ancient Chinese divination tool) to make major decisions about the plot and characterization in the book. In the novel, writer Hawthorne Abendsen also uses the I Ching to write his own alternate historical novel, The Grasshopper Lies Heavy; through consulting this ancient oracle, Abendsen is able to incorporate inner truth in his book.
One of the works that inspired Dick to write about an Axis victory was Bring the Jubilee, Ward Moore's 1953 novel that depicts an alternate history in which the Confederacy won the Civil War.
The novel was adapted into a television series on Amazon Prime in 2015. The series contains a number of changes to the book, including new characters and a plotline based on violent resistance to the Japanese occupation. The series received good reviews; for example, Meredith Woerner from the science fiction website io9.com writes, "I can honestly say I loved this pilot. It's an impressive, streamlined undertaking of a fairly complicated and very beloved novel."
The Man in the High Castle has become a classic of both science fiction and historical fiction, as well as one of Dick's most popular novels. It won the Hugo Award in 1963.