Europe 297: Second Battle of Carrhae
In late 296 war broke out between Sasanian Persia and the Roman Empire. Distracted by a revolt in Egypt in early 297, Diocletian sent Galerius with a reduced force to confront the Persians. Galerius met Shah Narseh in battle between Carrhae and Callinicum, but was heavily defeated.
The Agri Decumates was lost to the Romans in c.262, regained by Aurelian and Probus in 275–8, and lost again sometime between 290 and 310. The losses here seem not so much due to any rise in power of the local Alemanni tribe, but Roman internal division. When rival Roman factions controlled Gaul and Raetia, as was the case in 262–274 and 306, the limes of the Agri Decumates were no longer defensible and had to be abandoned.
Capitals of the First Tetrarchy
Officially, Rome remained the capital of the Roman Empire throughout the Tetrarchy. In practice, the real capital was wherever Diocletian’s court—and to a lesser degree, that of the other tetrarchs—resided. This varied considerably in the East, where Diocletian was initially based at Sirmium, in the Balkans, then joined Galerius in Antioch, before finally swapping places with his Caesar altogether by taking command at Antioch and Nicomedia while Galerius took charge in the Balkans (at Thessalonica and then Serdica). In the West the situation was less fluid: except for providing some brief support on the Rhine and a few years spent in Spain and Africa, Maximian remained based at Mediolanum, in Italy; his Caesar, Constantius, was largely based at Augusta Treverorum, in Gaul.
296–297 Narseh’s Roman campaign▲
In late 296 war broke out between Sasanian Persia and the Roman Empire. Shah Narseh first invaded the Roman client state in western Armenia, then overran Roman Mesopotamia and Osrhoene. In the spring of 297 he defeated Galerius near Carrhae, but does not appear to have followed through from this victory by advancing beyond the Euphrates.
296?–298 Maximian’s Moorish campaigns▲
In the 290s, probably following his successful support of Constantius’ invasion of Britain in 296, Maximian traveled to Spain, where he dealt with Moorish raiders from North Africa. After this, in around the spring of 297, he moved to Africa itself, where he mounted a campaign against the Quinquegentiani. These tribes he drove into the desert by 10 March 298, after which Maximian stayed in Africa for a time, before returning to Italy by the end of the year. It is probably during this period that the Baquates agreed to become Roman clients, safeguarding the land route between Mauretania Caesariensis and Tingitana.
297 Picts and Scoti▲
In 297, or slightly earlier, the Picts and Scoti—two previously unrecorded tribes—attacked Hadrian’s Wall, which had been weakened after Allectus appropriated its garrison to defend against Constantius Chlorus’ invasion of Britain. The Picts (meaning either “the painted ones” or “the ancestors”) were probably just the original Caledonians under a new name; whether or not they spoke a Celtic language is uncertain. The Scoti were Gaelic-speaking raiders from Hibernia (Ireland), who would later give their name and language to Scotland.
297? Roman Dioceses▲
As a result of Diocletian’s reforms, the Roman Empire came to contain over 100 provinces. To facilitate their management, these provinces were grouped together into twelve larger units known as dioceses, with three dioceses for each of the tetrarchs. Each diocese was placed under the authority of a subordinate of the praetorian prefect, known as a vicarius. Most modern historians believe that the dioceses were created in around 296–297, although it is possible that they were introduced as late as 314, during the reign of Constantine.
297–298 Domitius Domitianus and Achilleus▲
In 297 Domitius Domitianus proclaimed himself emperor in Egypt, probably with the support of the corrector Achilleus (ancient historians talk only of Achilleus whereas surviving coins are only of Domitianus). The rebellion forced Diocletian to leave the Persian campaign in the hands of Galerius while he himself marched south and quickly defeated Domitianus. Diocletian then besieged Achilleus in Alexandria, which finally fell after an eight-month siege. In retribution, Diocletian had the traitors put to death and ordered a massacre of many of the people in the city.
297 Second Battle of Carrhae▲
As Diocletian was forced to deal with the revolt in Egypt, he sent his Caesar Galerius at the head of a depleted Roman force to confront the Persian invasion of Syria. Galerius engaged the army of Shah Narseh between Callinicus and Carrhae, but the Romans were completely overwhelmed by the superior Persian numbers and fled the battlefield. As a sign of his displeasure at this outcome, Diocletian allegedly made Galerius run alongside his chariot for several miles in his robes, but kept him on as commander.