François Ier d'Autriche
Ferdinand was the eldest son of Francis II, Holy Roman Emperor and Maria Theresa of Naples and Sicily. Possibly as a result of his parents' genetic closeness (they were double first cousins), Ferdinand suffered from epilepsy, hydrocephalus, neurological problems, and a speech impediment. He was educated by Baron Josef Kalasanz von Erberg, and his wife Countess Josephine von Attems.