all attempts to move the date of the castra structure which is now visible in the historic centre of Albano back. These attempts included the aforementioned Giovanni Antonio Ricci, who dated the encampment to the Second Punic War (219 BC-202 BC), the Jesuit priest Giuseppe Rocco Volpi who thought it dated to Augustus and Tocco who decided that it was the acropolis of Alba Longa. The date universally considered correct for the castra is starting in the reign of Septimius Severus (193-211), who came to the throne after the Year of the Five Emperors and a violent civil war and thought it best to temporarily dissolve the Praetorian Guard and bring the Legio II Parthica near Rome for his personal and political security. This legion had been created in 197 for the (successful) campaign against Parthia which ended in 198 with the sack of Ctesiphon (near modern Baghdad, Iraq). The site chosen for the foundation of the castra, which might seem unsuitable due to the steep slope of the terrain, was actually an excellent position with a panoramic view - ideal for the point of observation of the Ager Romanus which the camp was to be. An incident related to the castra occurred in the Principate of Caracalla (211-217), who came to power after assassinating his brother and co-emperor, Geta. This fratricide angered the Legio Parthica, which insisted that it had sworn fialty to both the sons of Septimius Severus and refused to accept Caracalla as sole emperor. He went in person to Castra Albana and after a long meeting with the legionaries he convinced them to remain loyal, by promising to increase their stipend by fifty percent and to improve the camp by having the imposing Baths of Caracalla erected. The documentary evidence shows the last trace of the legion's presence at Castra Albana in 226 AD, although the legion had been active in campaigns abroad from 208-11 AD (in Britain) and afterwards under Caracalla against the Germanic tribe of the Alamanni in 213. Next, the legion was again sent to Parthia and their commander Macrinus was responsible for Caracalla's murder in that region in 217. In the following year, however, the II Parthica, stationed in Apamea (Syria), abandoned Macrinus and sided with Elagabalus; the Second supported Elagabalus' rise to purple, defeating Macrinus in the Battle of Antioch. The legion is mentioned in the ancient literary sources again in