Proculus, in full Titus Ilius Proculus, was, according to ancient sources, a usurper between 280 and 281 A.D. in the reign of the emperor Marcus Aurelius Probus.
A native of Albingaunum (modern Albenga), where his family belonged to the local nobility, he became wealthy by trading in cattle and slaves, which he got by brigandage.
At Albenga he lived with his wife Vituriga and his son Erennianus, after a brilliant military career in which he was appointed to the rank of tribune in several legions.
The writer of the Vita Probi in the Historia Augusta states that in 280 A.D. he accepted the purple offered to him by the people of Gaul and took as colleague another usurper, the tribune Bonosus. According to some sources this happened at Colonia Agrippina, according to others, at Lugdunum.
Confirmation on the identification of the place of his elevation comes from the known coinage in his name, which, as we will see later, indicates Cologne as the most probable location.
Proculus is said to have guaranteed security to the inhabitants of the province by defeating the Alamanni. This information from the Historia Augusta shows how the usurpation was itself a response to the need felt by the population living close to the borders and threatened by enemies, to have the emperor and his army close at hand.
The return of the legitimate emperor to the region forced Proculus to retreat northwards, where he sought help from the Franks, who instead betrayed him and handed him over to Probus. The emperor condemned Proculus to death, but the family and assets of the usurper were spared.
The historical context
After Aurelian’s victory over Tetricus in 274 A.D. which ended the Gallic Empire and brought back under Roman control the territory formerly held by the usurper, troops stationed on the limes were withdrawn in anticipation of war against the Goths, a decision which in reality opened the gates to invasion.
Already in 275 Aurelian had crossed the Alps, according to the Historia Augusta, to defend parts of Rhaetia, in particular Augusta Vindelicum which was beseiged by the barbarians. At the end of Aurelian’s reign problems persisted in those areas bordering the Rhine which were no longer defended by the usurpers of the Gallic Empire.
The same area continued to be a concern in the reign of Tacitus (275-276 A.D.): the staff of the Lugdunum mint were transferred to Arelate.
Barbarian attacks against the Rhine area, Gallia Lugdunensis, and the north of Italy were a problem Probus (276-282 A.D.) would have to confront, after defeating the Goths on the Danube and in Asia Minor.
In numismatic circles, the fact that a great army was put together to repel these invasions is highlighted by a typological series of busts in which Probus is shown in military dress.