The building occupies the highest part of the cliff at a point that rises from 320 to 330 meters above sea level. Presumably the actual construction replaced preexisting structures, perhaps of wood, that stemmed from the very first settlements there of certainly of lesser scale. This is evident from the fact that the fortress follows the outline of a wall that was probably older and surely of a different material, and also from the location of the tower in the surroundings of the building portion, which experts believe is of older construction. Local historians also support this hypothesis. Father Giovanni Fiore da Cropani maintains that the castle existed from the most ancient times and crumbled for the first time during the earthquake that followed the death of Jesus Christ. But, the Abbot Pacichelli attributes its founding to Frederick Barbarossa.
Lupis maintains that it was built by the Graeco-Bruzzi people, as a result of the abandonment of the area now called Terravecchia and their move to the highest and safest place on the plain. Don Antonio Fiore similarly believed that those who built it where local inhabitants who had abandoned their old city in the wake of some calamity. Pasquale Giuliani writes that the castle dates from the Norman era, but that a more ancient nucleus already existed there in the time of King Teia. What is certain is that the most ancient remains, even though scanty, are of Norman origin, and that the castle was enlarged in successive historical periods up to our time.
to the charter of foundation of the Benedictine abbey in 1062 by Robert
Guiscard, there is no mention of the castle, either because it hadnít
been built, or else because it was a structure of no account. By 1122,
on the other hand, the castle had already been built, inasmuch as Pope
Calixtus II stayed there for fifteen days. In 1198, it was restored by
order of Constance of Hauteville, and in 1235 by her son Frederick II.
The work was finished in 1238. According to some historical sources, this
effort was limited to restoring the tower portion, and integrating it
to its whole defensive system, and to enlarging the perimeter towards
the lower section, which delineated the area to be defended. From these
same sources one gathers that in this period the castle didnít have a
walled encirclement, and that it depended on the impregnability of its
site that was guaranteed by the tower whose access must have been particularly
subject to military protection, something which implies the existence
at that time of some sort of fortification.