[1] The castle was built around an existing Lombard tower dating back to the 9th century, guarding the pass of the Popoli gorges, protecting the Abbey of San Clemente a Casauria.

In the mid-11th century, the castle was seized by Count Ugo Malmozzetto of Manoppello, who imposed strict control over the valley on behalf of Robert I of Loritello, and entrusted it to his lieutenant.

The Chronicon Casauriense recounts an anecdote in which Count Ugo, a ruthless and power-hungry man, was lured to the castle, known in documents as "Castrum Pauperim", in 1097 by a princess from the nearby fort of Prezza, and was subsequently captured and killed by her brothers who had set the ambush.

Initially, the triangular enclosure housed the population for protection against attacks, but from the 13th-14th centuries, as the settlement of Popoli Terme developed in the valley, the oldest part, located between the churches of San Lorenzo and the Holy Trinity, lost its strategic importance.

After the 2009 earthquake, a serious consolidation effort was necessary, including the restoration of the towers, completed between 2012 and 2015, and the enhancement of the ascent path from the Popoli Terme village, originally laid out in the 1920s by the famous engineer Corradino D'Ascanio.