The Blazing World

"Though I cannot be Henry the Fifth, or Charles the Second; yet, I will endeavour to be, Margaret the First: and, though I have neither Power, Time nor Occasion, to be a great Conqueror, like Alexander, or Cesar; yet, rather than not be Mistress of a World, since Fortune and the Fates would give me none, I have made One of my own."

A truly grand mission statement, and one admirably achieved in this Sci-Fi classic from 1666 which outgrew its Royal Society origins to became one of the first SF novels, and a founding text of feminist, utopian, and fantasy fiction.
A young lady is abducted, shipwrecked, and passes into the Blazing World, where it is never dark. When its Emperor beholds the stranger, he believes her a divine spirit. She becomes Empress, granted absolute power to shape the world as she sees fit.
There, bird-men, mer-men, fox-men, and the first fictional spider-men walk and talk as full citizens. In a scientific conference, Bear-men experimental philosophers peer through microscopes and telescopes; Ape-men chemists debate the Philosopher's Stone and a rejuvenation substance that grants youth and health for hundreds of years; Bird-men astronomers argue over suns, moons, and a plurality of worlds; Fish-men explain tides and salt seas; Spider-men mathematicians spin points and lines so thin they seem "non-beings."
There are submarines, incendiary weapons, bombers, and hard speculative science.
The Empress meets a spirit from our world: the author herself, the Duchess of Newcastle, scarred by the English Civil War and the exile and impoverishment it brought her family. With the Duchess's help, she creates new imaginary worlds to conquer. But when her home nation is imperilled, the Empress builds an invasion fleet, crosses back, and conquers her native world.

Scientific satire, feminist manifesto, a tale of three worlds, an interplanetary invasion, by a woman who, denied a kingdom by fortune, makes one of her own.