Prelude in Prague — S. Fowler Wright

In 1935 S. Fowler Wright penned the first volume of an SF trilogy based on the notion--then considered absurd--that Adolf Hitler was an evil, empire-seeking megalomaniac bent on conquering the world. First Hitler rearms Germany, then forces Europe to accept the German occupation of Austria, and finally gives Czechoslovakia an ultimatum: accept German rule--or be conquered! The first book of a thrilling alternate history of World War II.