# Galerius' Sasanian Campaigns

The Sasanian campaigns of Galerius were a series of military expeditions which saw the Romans and the Persian Sassanids clash, which were part of a war that lasted overall from 296 to 298 AD, which culminated in the Battle of Satala. With his accession to the throne Narseh had clearly expressed his intention to break the peace treaty signed in 287 between Diocletian and Vahram II, which had put an end to sixty years of wars between the Persians and the Romans, began with the rise of the new Sasanian dynasty of Artaxerxes.
According to Eutropius, the campaign had already begun in 293, with the invasion of the Roman province of Syria, but it was only in 296 that the caesar Galerius, received from Diocletian (intended to quell a revolt in Egypt) the task of undertaking a military campaign against the Sassanid ruler Narseh, who ascended the throne three years earlier.

## Historical context
### Diocletian and the Tetrarchy

In 285 the Emperor Diocletian came to power and, in order to more easily defend the Empire, attacked on all fronts by the barbarians, he decided to associate Maximinus Daza with power, appointing him first Caesar and then Augustus and entrusting him with control of the west. Later, however, he understood that two emperors were not enough to defend the Empire from the barbarians and appointed as Caesars two generals who distinguished themselves in battle, Constantius Chlorus and Galerius. Thus the tetrarchy was born; the four tetrarchs (two caesars and two augusts) divided the Empire between them: Thrace, Egypt and Asia went to Diocletian; to Maximinus Italy and Africa; to Galerius the Illyrian provinces; to Constantius Spain, Gaul and Britannia. The caesars were subordinate to the two Augusti and upon the death or abdication of the Augusti they would in turn become Augusti and would appoint two caesars. Diocletian's tetrarchic reform made the defense of the provinces more effective and slowed down the crisis of the Empire.

### The revolt of Tiridates

According to several modern authors, the casus belli of the conflict should be identified in the Roman desire to reinstate one of their client kings on the throne of Armenia. Under the reign of Valerian Armenia was conquered by the Sasanian Persians who assassinated the Armenian king Chosroes. The latter's son, Tiridates, managed to escape to Roman territory where he was placed under the protection of the emperor. The Armenian sources, which also have problems of reliability, exalt Tiridates' skills and courage and state that he was a very athletic young man and possessed immense strength; one day he would have saved Licinius (whose identification with the future emperor is not certain) from an attempted lynching by stopping the attackers with his arm alone.
According to Gibbon, Licinius, as a sign of gratitude towards Tiridates, pressured the tetrarchs to help him recover the throne. In any case, according to Armenian sources, in the third year of Diocletian's reign Tiridates was invested with the Kingdom of Armenia. Diocletian's panegyric attests to a treaty of Diocletian with Persia in that same year, by which the Persian king Bahram II presumably recognized Tiridates III as king of Armenia. The gifts received from Bahram II were interpreted as the symbols of a Roman victory over the Sasanians (of which the solution of the Armenian question constituted the substantial aspect), so much so that Diocletian was hailed as the "founder of eternal peace". These events may have represented the formal end of the Sasanian campaign of Carus and Numerian, which probably ended without the conclusion of a real peace treaty.
According to Gibbon, the Armenian population poorly tolerated Persian domination and welcomed the return of Tiridates to their throne with Roman support. The command of the army was entrusted to Artavasdes, to whom the king was very grateful because he had saved his life from the Persians when he was little. Gibbon also claims that the Shah of Persia sent to Armenia Mamgo, a prince originally from Scythia who was in command of a horde of his countrymen, with orders to repress the revolt, but, due to the offenses received from the Shah, Mamgo himself decided to join the rebels, contributing very effectively to the restoration of Tiridates.

## Timeline
### 294

In 294, Narseh, a son of Shapur I, who had been passed over for the Sassanid succession, came into power in Persia. Narseh probably moved to eliminate Bahram III, a young man installed by a noble named Vahunam in the wake of Bahram II's death in 293. In early 294, Narseh sent Diocletian the customary package of gifts, but within Persia, he was destroying every trace of his immediate predecessors, erasing their names from public monuments. He sought to identify himself with the warlike reigns of Ardashir (r. 226–241) and Shapur (r. 241–272), who had sacked Roman Antioch and captured Emperor Valerian.

### 295

Due to a civil war in Persia, the rebels of Tiridates managed not only to free Armenia from the Persian yoke but also to penetrate Assyria. However, when the civil war ended, the new shah Narses, who ascended the throne in 293, managed to regain control of Armenia with a victorious military campaign. Once again Tiridates lost his throne and once again took refuge in Roman territory. The historian Ammianus Marcellinus, c. 320–395, is the only source detailing the initial invasion of Armenia. Pat. Southern dates the invasion to 295, while Timothy Barnes mentions an earlier, unsuccessful invasion by Narseh based on the fact that the title Persici Maximi was given to all four emperors; Odahl (2004, 59) concurs with Barnes and suggests that Saracen princes in the Syrian desert collaborated with Narseh's invasion.

### 296 (or 297)

Narseh, to punish the Romans for having supported the Armenian revolt, invaded the Roman province of Syria. At this point the Romans decided to actively help Tiridates to ascend the throne of Armenia; Diocletian established his base in Antigonia and entrusted the command of military operations to Galerius. Narseh then moved south into Roman Mesopotamia, where he inflicted a severe defeat on Galerius and was forced to retreat, then commander of the eastern forces, in the region between Carrhae (Harran, Turkey) and Callinicum (Raqqa, Syria). Diocletian may or may not have been present at the battle, but presented himself soon afterwards at Antioch, issuing an official version of events which placed all the blame for the affair upon Galerius. In Antioch, Diocletian forced Galerius to walk a mile in advance of his imperial cart while still clad in the purple robes of an emperor. David Stone Potter reads a symbolic message in the display: the loss at Carrhae was due not to the failings of the empire's soldiers, but to the failings of their commander, and Galerius' failures would not be accepted. Another scholar, Roger Rees, suggests that Galerius' position at the head of the caravan was merely the conventional organization of an imperial progression, designed to show a Caesar's deference to his Augustus.
Gibbon arbitrarily attributes to this battle an episode handed down by Armenian sources according to which, at the end of a defeat suffered against Persia, Tiridates, who had fought bravely, was chased up to the Euphrates and miraculously saved himself swimming across the river (at least half a mile deep at that point) in very heavy armor. The reasons for the defeat are commonly attributed to the imprudence of Galerius who attacked the Sasanians with an insufficient number of troops.: Galerius was received coldly by the Emperor and was forced to follow the imperial chariot on foot for more than a mile. Yielding to Galerius' pleas, Diocletian decided to reconfirm him as army command. Galerius was intent on avenging the humiliation suffered and, by Winter of 297, at the head of an army of 25,000 men (coming mostly from Illyricum and Moesia), crossed the Euphrates again but instead of invading Mesopotamia he decided to cross the mountains of Armenia, where he received the support of the local inhabitants.

### 298

Galerius's army was reinforced probably in the spring of 298 by new contingents collected from the empire's Danubian holdings. Narseh did not advance from Armenia and Mesopotamia leaving Galerius to lead the offensive in 298 with an attack on northern Mesopotamia via Armenia. Diocletian may or may not have been present to assist the campaign. Narseh retreated to Armenia to fight Galerius' force, putting himself at a disadvantage; the rugged Armenian terrain was favorable to Roman infantry, but not to Sassanid cavalry. Local aid gave Galerius the advantage of surprise over the Persian forces, and he defeated Narseh in two successive battles. During the second encounter, the Battle of Satala in 298, Roman forces seized Narseh's camp, his treasury, his harem, his wife and inflicted huge losses on the Persians. Narseh's wife, Arsane, was captured during the fighting and would live out the remainder of the war in Daphne, a suburb of Antioch, serving as a constant reminder to the Persians of the Roman victory, while another of his wives, Shapurdukhtak, was imprisoned. In the chaos, Narseh himself sustained a light wound during the fighting, but managed to flee soon after.
Galerius advanced into Media and Adiabene, winning continuous victories, most prominently near Theodosiopolis (Erzurum), and securing Nisibis (Nusaybin) before 1 October 298. The historian Timothy Barnes argues that he moved down the Tigris, taking Ctesiphon. Barnes main argument for this is that Eusebius' biography of Constantine mentions that the later emperor had seen the ruins of Babylon according to this work. Patricia Southern also argues that he took Ctesiphon based on the uncertainty of the location where the seizure of Narseh's wife and harem took place. However, no source ever specifically claims that Ctesiphon was sacked and many other historians argue Diocletian prevented him from moving further into Sasanian territory. The two sides then met in a peace treaty in Nisibis. The Persian ambassador Afarbanus, after praising the victor of the war without belittling his king, appealed to the moderation of the Romans, recalling with an oriental allegory that Rome and Persia are the two eyes of the world and that if one of the two were blinded the world would be imperfect and mutilated. According to Peter the Patrician, Galerius' response would have been the following:
   «It is well suited to the Persians to dwell on the vicissitudes of fortune and to admonish us on the virtues of moderation. Let them remember their moderation towards the unfortunate Valerian. They defeated him by deceit and imposed on him an unworthy treatment. They kept him in shameful captivity until the last moments of his life and after his death they exposed his body to perpetual ignominy.» (translated)
After reassuring him that the Romans were not accustomed to trample on a defeated enemy, Galerius dismissed Afarbanus.

### 299: peace treaty

Diocletian and Galerius, after meeting in Nisibis, sent Sicorius Probus, one of their secretaries, to communicate the conditions for peace to the Persians. Probus was welcomed with all honors by the Persians but his audience with the Sasanian king was postponed from day to day under various pretexts; according to Gibbon Narses presumably intended to gain time to gather an adequate army, so that he could negotiate peace with greater dignity. When the day of the hearing finally arrived, Probus communicated the conditions for peace to the Shah:
* The city of Nisibis, where peace was signed, must be the hub of trade of the two empires;
* Armenia and Iberia become client kingdoms of the Romans;
* The border between the two empires is set on the Tigris river while the border between Armenia and Persia is set near Zintha, a fortress of Media on the border with Armenia;
* The Persians cede five regions beyond the Tigris: according to Peter the Patrician, they were Intelene, Sophene, Arzanene, Zabdicene and Carduene; according to Ammianus Marcellinus, instead, the five ceded regions would have been the Zabdicene, the Arzanene, the Moxoene, the Carduene and the Rehimene.
Narsetes only opposed the first point, which however he was forced to accept in the face of the firmness of the Romans. After the Stipulation of the treaty, Narses' relatives who had been taken prisoner by the Romans were returned.

## Consequences

Diocletian celebrated his triumph on the occasion of the twentieth anniversary of his accession to the throne (in 304):
   «The arduous task of defending the troubled empire from tyrants and barbarians had now been completed by a series of Illyrian peasants. Entering his 20th year of reign, Diocletian celebrated that memorable date, and the success of his arms, with all the pomp of a Roman triumph. [...] Africa and Britain, the Rhine, the Danube and the Nile provided their respective trophies, but the most splendid ornament was of a more singular nature: a Persian victory followed by a major conquest. Representations of rivers, mountains and provinces paraded in front of the imperial chariot. The images of the wives, sisters and children of the Great King, prisoners, constituted a new and gratifying spectacle for the vanity of the people. In the eyes of posterity this triumph is noteworthy for a less glorious reason: it was the last that Rome could witness. Before long, the Emperors ceased to win and Rome ceased to be the capital of the Empire.
Mesopotamia returned under Rome for 40 years of peace (the frontier was moved up to Khabour, to the Tigris, passing through the Djebel Sindjar), the Armenia was recognized as a Roman protectorate together with Iberia, while in Nisibis the caravan routes for trade with the Far East (China and India) were centralised, but above all the construction of the military road of the frontier began east of the strata Diocletiana. It appears that the five regions beyond the Tigris had not come under direct Roman control, but were governed by local satraps who recognized the supremacy of Rome; Furthermore, it cannot be excluded that they had been annexed to Armenia, a client kingdom of Rome. Galerius later celebrated his victory (between 298 and 303), erecting an arch dedicated to him in Thessalonica, although it seems not to have welcomed the peace treaty, as he would have wished to advance further into Persian territory.