The name of this mountain town is derived from the Latin word ‘petra’ for stone and so the countryside is stony. In 1598 in Rocca di Petrella one of the most famous sixteenth-century crimes took place, the murder of Count Francesco Cenci, arranged by his daughter Beatrice.
The earliest records of Petrella date back to the twelfth century when it was a fiefdom of Gentile Vetulo who succeeded the Mareri, the most powerful family of the rural nobility of the area. In the second half of the thirteenth century Petrella, whose fortress was manned by a length of royal garrison, was granted to Mareri and bestowed upon Guillaume Accrochemoure from Provençal, and then Pietro Colonna.
In 1295 Charles II of Anjou return the castle to Thomas Mareri and Petrella became the centre of their barony. The Emperor Charles V, then assigned it to Marzio Colonna. Then came the Barberini and, upon their death, it became part of the Kingdom of Naples.