After a long and exhausting period of internal fighting and the fall of the free Commune, Orvieto remained annexed to the Pope Domains. Cardinal Egidio Albornoz, who was chief of the Papal Army, ordered the construction of a defensive fortress, placed above the gate called "Porta Soliana", in a strategic access point to Orvieto.

In 1364 the construction of the fortress was commissioned by Ugolino from Montemarte (an architect for the Albornoz family). The fortress was built on a four-sided structure surrounded by a wide ditch and some drawbridges, which can be seen in several old paintings.

After several demolitions and structural updates in the following years, the fortress lost its original military function, in 1841 an amphitheater was built inside, with stairs and stages where people could enjoy horse races and popular events.