The Moon Maid by Edgar Rice Burroughs

The Moon Maid is a fantasy novel by American writer Edgar Rice Burroughs, belonging to the Lost World sub-genre. It was written in three parts, Part 1 was begun in June 1922 under the title The Moon Maid, Part 2 was begun in 1919 under the title Under the Red Flag, later retitled The Moon Men, Part 3 was titled The Red Hawk. As evident from its name, Under the Red Flag was originally set in contemporary Soviet Russia, with the Bolsheviks as villains; as this was not popular with the publishers, Burroughs transferred it to a science-fictional setting, with the evil Communist-like "Kalkars" taking over the Moon (in the first part) and then the Earth (in the second part, with the help of a renegade Earthman) and being finally overthrown in the third part. (Also the Thorists, villains of Pirates of Venus, are clearly modeled on the Russian Communists.)
The book version was first published by A. C. McClurg on February 6, 1926, under the title The Moon Maid, though it was shortened from the serial. The three Parts have been published in varying combinations and under varying titles since 1926.