Wild Seed, by Octavia E. Butler
Apparently, this is considered one of the late Ms. Butler's "lesser works." It doesn't merit its own Wikipedia entry, it didn't win any major awards, and I haven't seen it on any must-read lists of science fiction/fantasy.
Frankly, I'm surprised, because, after my third reading, I am still overwhelmed by how incredibly rich Wild Seed is.
Published in 1980, the novel spans about 150 years of time in the lives of two immortals. The first, and oldest is Doro, whose existence is sustained by his ability to steal the body of the person closest to him, either when his current body naturally dies, or, much more disturbingly, whenever he wants to make a point. Doro is a menacing figure, both alien and human, who has lived millennia before the novel's opening, attempting to breed a race of superhuman descendants via a eugenics program whose scope and methodology would make Josef Mengele look like a slacker.
In all his existence, Doro has never met another person with even the potential for immortality. This changes in 1690 when, after finding one of his "seed villages" in Africa destroyed by marauding slavers, he feels the pull of a powerful presence.
He seeks out and finds the source of his attraction in the person of Anyanwu, a healer and shape changer who can control her body almost absolutely and has lived many lives of her own by appearing to grow old and then relocating for a time before returning as a young woman to the people who do not recognize her as their grandmother or great grandmother.
These two characters meet on page four. The following 275 pages are an epic account of their unique and disturbing relationship and the book as a whole is one of only a small handful that have ever inspired me to read them more than twice. Race and culture, love and bitter hatred, and the struggles of virtually immortal beings to retain their humanity all combine to make Wild Seed a gripping tale.
Though it is categorized as "fantasy," those of you who are geeky enough to distinguish between flavors of fantasy might notice that it is effectively a "supers" tale, albeit in a very unusual setting. Doro's children, his experiments both successful and failed, are reminiscent of the mutants of the X-Men series -- terrifying to the general population and often tortured by the very powers that make them different.
The book is also very reminiscent of the better parts of Anne Rice's Interview With the Vampire. Like Interview, much of it occurs in the antebellum south and the timeless natures of Doro and Anyanwu and their tenuous and tragic attachments to the mortal world have many parallels with the descent of Louis into Lestat's world.
Butler was probably the most prominent African-American science fiction/fantasy writer of her time, and certainly the most prominent African-American woman in the field. If Wild Seed isn't her best, then there are some amazing books out there I still haven't read.