Tutankhamen was inbred.
It really explains why he had the health issues he had. Inbreeding is extremely dangerous but I don't really know why.
So don't do it.
inbreeding is bad because a lot of genetic diseases/afflictions are recessive and by breeding with your own genetic line you increase the probability of getting that recessive trait to show itself.
its why purebred dog lines tend to have dogs with more genetic issues like arthritis.
@op:
bloody mary's diagram is the most organized you can make it, and how its done in literature (for example, the greek pantheon)