The younger brother of King Henri II of France died in 1545, presumably of the plague. The treaty of Crépy promised him in marriage to either the emperor's daughter or niece. That said, either marriage would've been a statistical nightmare for France with Angoulême controlling almost as much land within France as without (note: this was probably HRE Karl V's intention).
As with his eldest brother, the Dauphin, there would've been the concern of not wasting him in marriage as many believed Henri II had been to Catherine de Medici. Now Henri II's sons suffered from abysmal bad luck - one was dead by 16; one died in infancy; another was mad and left only a daughter;a third was not the man who could control France; and the youngest had no talent to rule (see French fury in the Netherlands) - in addition to their bad health (how much was inherited I don't know, but Anne of Brittany, Claude de France and Catherine de Medici were not paragons of health. Claude de Valois, duchess of Lorraine (Catherine's daughter) is said to have been cursed by inheriting all of the bad health that her mother brought with her, while La Reine Margot got off relatively scot-free.)
Who would Angoulême marry if not one of the archduchesses? Where would he come down during the wars of religion, Protestant or Catholic? What might Henri II's reign look like with Angoulême's survival?
Looking forward to thoughts and opinions.