Frederick III, Holy Roman Emperor
The "Castel San Giusto", or Castle of San Giusto, was designed on the remains of previous castles on the site, and took almost two centuries to build. The stages of the development of the Castle's defensive structures are marked by the central part built under Frederick III, Holy Roman Emperor (1470–1), the round Venetian bastion (1508–9), the Hoyos-Lalio bastion and the Pomis, or "Bastione fiorito" dated 1630.