Her third-surviving son became Ferdinand I of the Two Sicilies , while his elder brother Carlos was groomed in Spain to inherit the Spanish crown ; their oldest brother , Infante Felipe , Duke of Calabria was mentally retarded and was thus taken out of the line of succession to any throne ; he died quietly and forgotten in Portici where he had been born in 1747 .
Her third son became Ferdinand I of the Two Sicilies , while his elder brother Infante Charles was groomed in Spain to inherit the Spanish crown .