Well, it is incredibly seamy. BTW, if you're wondering where the advantage lay for Pope Alexander VI., otherwise known as Rodrigo Borgia, in granting Louis XII his suit: an alliance, a dukedom and a bride of royal blood for son Cesare. Charlotte d'Albret, who marred Cesare Borgia, was Louis XII' niece. If you remember how even centuries later aristos like Liselotte are upset when their son marries a bastard daughter of Louis XIV (even a royal bastard is still a bastard), you can imagine that the illegitimate son of a Spanish Pope (his being Spanish upset a whole lot of Italian aristocrats way more than his being standard Renaissance corrupt) getting to marry into the French Royal family was really a major coup.
Re: Harold Acton: Last of the Medici I: How to make really bad marriages