Galerius
Galerius Valerius Maximianus was Roman emperor from 305 to 311. He participated in the system of government later known as the Tetrarchy, first acting as caesar under Emperor Diocletian. In this period Galerius obtained victory warring against the Persian Sasanian Empire, defeating Narseh at the battle of Satala in 298 and possibly sacking the Sasanian capital of Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300. Galerius was promoted to augustus upon the abdication of Diocletian in 305, but had to contend with multiple usurpers as the Tetrarchic system broke down. Although he was a staunch opponent of Christianity, he ended the Diocletianic Persecution by issuing the Edict of Serdica in 311.
Early life
Galerius was born in the Danube provinces, either near Serdica or at the place where he later built his palace named after his mother – Felix Romuliana, in the province later known as Dacia Ripensis. Under this palace, an older villa has been found that is sometimes interpreted as Galerius's birthplace. His mother, Romula, had left Roman Dacia and settled in New Dacia south of the Danube because of the Carpians' attacks. He originally followed his father's occupation, that of a herdsman, where he was nicknamed "Armentarius", herdsman. His original cognomen was "Maximinus", but he changed it to "Maximianus" after becoming Caesar.He served with distinction as a soldier under Emperors Aurelian and Probus, and in 293, at the establishment of the Tetrarchy, was designated Caesar along with Constantius Chlorus, receiving in marriage Diocletian's daughter Valeria, and at the same time being entrusted with the care of the Illyrian provinces. After a few years campaigning against Sarmatians and Goths on the Danube, he received command of the legions on the eastern imperial limits. Soon after his appointment, Galerius was dispatched to Egypt to fight the rebellious cities Busiris and Coptos.
War with Persia
Invasion, counterinvasion
In 294, Narseh, a son of Shapur I, who had been passed over for the Sasanid 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 and Shapur, who had sacked Roman Antioch and captured Emperor Valerian.In 295 or 296, Narseh declared war on Rome. He appears to have first invaded western Armenia, retaking the lands delivered to Tiridates in the peace of 287. He occupied the lands there until the following year. The historian Ammianus Marcellinus, circa 320–395, is the only source detailing the initial invasion of Armenia. Southern dates the invasion to 295; Barnes mentions an earlier, unsuccessful invasion by Narseh based on the fact that the title Persici Maximi was given to all four emperors; Odahl concurs with Barnes and suggests that Saracen princes in the Syrian desert collaborated with Narseh's invasion. Narseh then moved south into Roman Mesopotamia, where he inflicted a severe defeat on Galerius, then commander of the eastern forces, in the region between Carrhae and Callinicum. 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's failures would not be accepted. Another scholar, Roger Rees, suggests that Galerius's position at the head of the caravan was merely the conventional organization of an imperial progression, designed to show a Caesar
File:Arch-of-Galerius-1.jpg|right|thumb|Detail of Galerius attacking Narseh on the Arch of Galerius at Thessaloniki, Greece, the city where Galerius carried out most of his administrative actions.
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's force, putting himself at a disadvantage; the rugged Armenian terrain was favorable to Roman infantry, but not to Sasanid 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, and his wife. Narseh's wife 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.
Galerius advanced into Media and Adiabene, winning continuous victories, most prominently near Theodosiopolis, and securing Nisibis before 1 October 298. The historian Timothy Barnes argues that he moved down the Tigris, taking Ctesiphon. Barnes's main argument for this is that Eusebius's 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.
Peace negotiations
Narseh had previously sent an ambassador to Galerius to plead for the return of his wife and children, but Galerius had dismissed this ambassador, reminding him of how Shapur had treated Valerian. In any case, the Romans treated Narseh's captured family well, perhaps seeking to evoke comparisons to Alexander and his beneficent conduct towards the family of Darius III. Peace negotiations began in the spring of 299, with both Diocletian and Galerius presiding. Their magister memoriae Sicorius Probus was sent to Narseh to present terms.The conditions of the Peace of Nisibis were heavy: Persia would give up territory to Rome, making the Tigris the boundary between the two empires. Further terms specified that Armenia was returned to Roman domination with the fort of Ziatha as its border; Caucasian Iberia would pay allegiance to Rome under a Roman appointee; Nisibis, now under Roman rule, would become the sole conduit for trade between Persia and Rome; and Rome would exercise control over the five satrapies between the Tigris and Armenia: Ingilene, Sophanene, Arzanene, Corduene, and Zabdicene. These regions included the passage of the Tigris through the Anti-Taurus range; the Bitlis pass, the quickest southerly route into Persian Armenia; and access to the Tur Abdin plateau. With these territories, Rome would have an advance station north of Ctesiphon, and would be able to slow any future advance of Persian forces through the region. Under the terms of the peace, Tiridates would regain both his throne and the entirety of his ancestral claim, and Rome would secure a wide zone of cultural influence in the region. Because the empire was able to sustain such constant warfare on so many fronts, it has been taken as a sign of the essential efficacy of the Diocletianic system and the goodwill of the army towards the tetrarchic enterprise.
Rule as Augustus
After the abdication of Diocletian in 305 and the elevation of Constantius I and Galerius to the rank of Augustus, two new Caesars were required to take their place. Seeking to enhance his authority, Galerius gave the positions to men who were very much his creatures. Maximinus Daza, a nephew of Galerius with little experience or formal education, was assigned the command of Egypt and Syria. Valerius Severus, Galerius's comrade in arms, was sent to govern Italy and Africa from a base in Mediolanum. Officially Severus reported to the western emperor, but he was absolutely devoted to the commands of his benefactor Galerius, whose power was thus established over three-quarters of the empire.Constantius died at Eboracum in 306 and the legions elevated his son Constantine to the position of Augustus. Galerius only discovered this when he received a letter from Constantine, who apologized for the informal nature of his promotion but nonetheless treated it as valid. The first emotions of Galerius were surprise, disappointment, and rage, and as he could seldom restrain his passions, he threatened to burn both the letter and the messenger. Calmer consideration made him reluctant to open a civil war: Constantine had the devotion of Constantius' legions, and the young man's character had impressed Galerius during an encounter at Nicomedia. Galerius decided on a compromise position, allowing Constantine to rule the provinces beyond the Alps but giving him only the title of Caesar and the fourth rank among the Tetrarchs. Severus received the title of Augustus.
File:Гамзиград 04а.jpg|thumb|Gamzigrad-Romuliana, Palace of Galerius in Zaječar, Serbia, today a UNESCO World Heritage Site
Soon afterward, Maxentius, son of Maximian and husband of Galerius's daughter Valeria Maximilla, rebelled in Italy. A need for additional revenue had caused Galerius to disregard Italy's traditional exemption from any form of taxation, and Maxentius exploited local indignation to declare himself emperor. An army led by Severus hastened to Rome, hoping to catch the usurper by surprise, but Maximian, who had previously commanded many of the invading troops, came out of retirement in support of his son. The army switched sides, and Severus was arrested and later executed.
Leaving his long-time friend and military companion Licinius to guard the Danube, Galerius personally invaded Italy with a powerful army collected from Illyricum and the East. He forced his way as far as Narni, within sixty miles of Rome, but skillful preparations by Maximian prevented him from capturing any territory along the way.
The strength of the enemy's position made Galerius send peace overtures to Rome, professing his fatherly affection for Maxentius and promising to be generous if the rebels cooperated. Maxentius refused the offer, and meanwhile compromised the loyalty of the invasion force by sending bribes to the Illyrian legions. Galerius was compelled to begin a withdrawal from Italy, and it was only with great difficulty that he managed to stop his veterans deserting him. In frustration, Galerius allowed his legions to ravage the countryside as they passed northwards. Maxentius declined to make a general engagement.
With so many emperors now in existence, in 308 Galerius, together with the retired emperor Diocletian and the now active Maximian, called an imperial conference at Carnuntum on the River Danube to rectify the situation and bring some order back into the government. Here it was agreed that Licinius would become Augustus in the West, with Constantine as his Caesar. In the East, Galerius remained Augustus and Maximinus remained his Caesar. Maximian was to retire, and Maxentius was declared a usurper.
Galerius's plan soon failed. Envious of Licinius's promotion, Maximinus also claimed the title of Augustus. Maximian, still not willing to retire, declared himself emperor in Arles in opposition to Constantine, who was campaigning against the Franks. An additional usurper, Domitius Alexander, arose in Africa, bringing the number of claimants of imperial power up to seven. Galerius maintained his seniority and ceased trying to encroach on the other emperors' domains; he spent his later years in recreation and in public works, such as an extensive logging and drainage project at Lake Pelso.