Alternative-history vampire science/fantasy by Stableford (The Third Millennium, 1985), a novelist with degrees in biology and sociology. Stableford details the sociobiology of vampires with a fineness that puts top vampirist Anne Rice in the shade as a cultural chronicler. His story largely is laid three centuries ago in England when the civilized world, led out of the Dark Ages by the rise of vampires, is governed by an aristocracy of vampires who rule by fear. Vampires seemingly cannot love or feel pain; females are barren, and males have a low sex drive. They feed on--and draw their number from--common men. But how do the vampires reproduce from the commoners? This question haunts Edmund Cordery, courtier to Richard the Lion-Hearted (a vampire, of course), who has just devised a microscope that reveals the small world of microbes that he thinks can help overthrow vampire rule if the spermatic base of vampirism can be found. When Edmund kills a lady vampire by purposefully inoculating himself with the black plague before she drinks his blood, his son Neil--a budding social revolutionary- -flees England, seeking the microbial code. Neil knows vampires don't pass on their ``emortality'' by magic--it's something to do with their blood. He joins a pirate band and goes to Africa, fabled homeland of vampires, and in the wonderfully described Uruba tribe finds himself in vampire paradise where the biology of vampirism is at last revealed. An asteroid ages ago struck here, carrying on it ``the breath of life''--emortality microbes, which are now carried in vampire semen, which in turn must be applied to an open wound to be effective.... After the huge vampire battle of the Spanish Armada, the story leaps three centuries ahead for a brief look into modern worldwide emortality as analyzed by microbiologist Michael Southerne, who has Cordery's Syndrome (he must die, never emortal, because his blood resists vampire microbes). Terrific vampire fiction, with well-humanized puppet characters.