The Swabian-Angevin-Aragonese Castle dominates the city and the Sanctuary and is topped by a tower known as the Giants’ Tower, whose origin is said to date back to the mythical King Pilunno II.
Historically it is ascertained that Ursus, bishop of Benevento and Siponto, had the Castellum de Monte Gargano built in the years 837-838 , the primitive nucleus of which underwent continuous extensions and rebuilding over the centuries. Given the importance of the shrine, it was the seat of the Norman counts, the Swabians, the Angevins and the Aragonese. According to chroniclers of the time, Robert Guiscard, lord of the honor of Monte Sant’Angelo, in the second half of the 11th century arranged for it to be rebuilt and for the town to be surrounded by walls. Under Swabian rule it rose to great importance, so much so that it was one of the castra exempta for which the non provisores castrorum but the emperor himself appointed the castellan, as noted in Frederick II’s Decree issued in Milan on October 5, 1239.
Under the Angevins it was used mainly as a state prison where Filippa of Antioch, wife of Manfredi Maletta, nephew of Frederick II, died. In the 15th century, between 1491 and 1497, the castle took on the appearance it retains to this day: the looming danger of Turkish invasions and the invention of firearms made radical interventions essential (most likely due to Francesco di Giorgio Martini) such as the construction of very high curtain walls with double order of windows, three strong towers one of which resembled the hull of a ship as antemural defense, the moat and the gateway equipped with a drawbridge. It came into the possession of Giorgio Castriota Scanderbeg and then of Grand Captain Consalvo of Cordova, and was sold by the latter’s heirs to the Grimaldi princes who were feudal lords until 1802 when Donna Maria sold it to the Municipality of Monte Sant’Angelo for debt.
In fact, the municipality only really became its owner in 1907 when it bought it back from the heirs of Cardinal Ruffo prince of Sant’Antimo who enjoyed the fiefdom at the behest of Ferdinand IV of Bourbon.
Today, the Castle, after major restoration, is among the most fascinating places and is one of the hubs of the city’s cultural life.