The Castra Praetoria (English: Praetorian Barracks) was a fortified military barracks in Rome, incorporated into the north-eastern edge of the Aurelian Walls. It was originally constructed to house the Praetorian Guard, the official bodyguards of the Roman Emperors. Its remains survive to this day.
The Castra were erected just outside Rome by order of the Praetorian Prefect Sejanus, between 20 and 23, during Emperor Tiberius' reign, to house the nine cohorts of the Praetorian Guard, the influential Imperial guard. When Emperor Aurelian encircled the city with walls, he had the barracks incorporated in the fortification.
Following the kidnapping of Bartolomeo d'Alviano's wife, Pantasilea Baglioni, the fortress was infiltrated by Ezio Auditore da Firenze and a contingent of Bartolomeo's mercenaries disguised as French soldiers. Octavian was killed in the surprise attack, and his forces abandoned the fortress not long after..
- The Castra Praetoria was the location of one of Clay Kaczmarek's Rifts.
- The gate that actually surrounds the fortress is inaccesible until Ezio assassinates the Baron de Valois.
- This is the largest French camp that could be found in Rome until the completion of of the memory "Au Revoir".