Caesar Galerius led the pagan movement against Christianity and arrived to bring up Diocletian against Christianity in the year 302: first Christian soldiers had to leave the army, later the Church's property was confiscated and Christian books were destroyed.

Detail of Galerius attacking Narseh on the Arch and Tomb of Galerius # Arch of Galerius | Arch of Galerius at Thessaloniki, Greece, the city where Galerius carried out most of his administrative actions

Diocletian believed that Romanus of Caesarea was arrogant, and he left the city for Nicomedia in the winter, accompanied by Galerius.

Galerius left the city for Rome, declaring Nicomedia unsafe.

Rumors alleging that Diocletian's death was merely being kept secret until Galerius could come to assume power spread through the city.

The 4th century AD Arch of Galerius and Rotunda | Rotunda of Galerius, one of several Roman monuments in the city and a UNESCO World Heritage Site.

In 295, emperor Galerius was defeated outside the city.

Galerius himself marched on Rome in the autumn, but failed to take the city.

The city subsequently expanded for a century and a half, it became a significant political and economical centre, moreso — it became one of the first Roman cities where Christianity was recognized as an official religion ( Еmperor Galerius ).

It was expected that Maxentius would try the same strategy as against Severus and Galerius earlier ; that is, remaining in the well-defended city of Rome, and sit out a siege which would cost his enemy much more.

The Arch of Galerius ( Gr.: αψίδα &# 32 ; του &# 32 ; Γαλερίου )( or Kamara, Gr.: καμάρα ) and the Rotunda ( ροτόντα ) are neighboring early 4th-century monuments in the city of Thessaloniki, in the region of Central Macedonia in northern Greece.

At the crux of the major axes of the city, the Arch of Galerius emphasized the power of the emperor and linked the monumental structures with the fabric of 4th-century Thessaloniki.

These rooms display architectural members from an Ionic temple of the 6 < SUP > th </ SUP > century bc, sculptures of all periods from Macedonia, exhibits from the excavations in the palace complex built by Galerius in Thessaloniki city centre, a reconstruction of the facade of the Macedonian tomb in Ayia Paraskevi, Thessaloniki prefecture, with genuine architectural members, and finds ( mainly gold artefacts ) of the Archaic and Classical periods from the Sindos cemetery.

Dioclesian begat Galerius, Galerius begat Constantine the Great the son of Helen, Constantine begat Con-stantius, Constantius begat Maximianus, with whom the British soldiers went from Britain, and he slew Gratian the Roman emperor, and held the government of all Europe ; and he did not dismiss the soldiers, which he brought with him from Britain to return to their country on account of their bravery, but gave them many provinces and countries, that is from the pool which is on the top of the mountain of Jupiter to the city named Cantguic, and until the western mound that is Cruc Ochideint ; and from those soldiers arose a nation which is called Lettau. 1 Maximianus therefore begat Owain, Owain begat Nor, Nor begat Solor, Solor begat Glywys, Glywys begat Gwynlliw, Gwynlliw begat the most blessed Cadoc of whom we are speaking.

The boldness of this Christian displeased Diocletian, and he left the city and made for Nicomedia to spend the winter, accompanied by Galerius.

He is later executed ( or forced to commit suicide ) after Emperor Galerius unsuccessfully invades Italy.

Galerius was born in Serdica, though some modern scholars consider the strategic site where he later built his palace named after his mother – Felix Romuliana ( Gamzigrad ) – his birth and funeral place.

Valerius Romulus, also Marcus Aurelius Romulus ( c. 292 / 295 – 309 ) was the son of the Caesar and later usurper Maxentius and of Valeria Maximilla, daughter of Emperor Galerius.

Diocletian and Maximian seem to have understood this when they set up Constantius Chlorus and Galerius as Caesars in Gaul and Illyria respectively some thirty-five years later.

Diocletian delegated further on 1 March 293, appointing Galerius and Constantius as Caesars, junior co-emperors.

* March 1 – Emperor Diocletian and Maximian appoint Constantius Chlorus and Galerius as Caesars.

Diocletians wife Prisca bore him a daughter Galeria Valeria, who married Galerius ( whom Diocletian had adopted and appointed caesar on March 1, 293 ).

* Marcus Galerius Aurelius Antoninus ( died before 138 ); his sepulchral inscription has been found at the Mausoleum of Hadrian in Rome.

A further massive transfer of Bastarnae was carried out by emperor Diocletian ( ruled 284-305 ) after he and his colleague Galerius defeated a coalition of Bastarnae and Carpi in 299.

Galerius, aided by Diocletian, campaigned successfully against Sassanid Persia, the Empire's traditional enemy.

In the spring of 293, in either Philippopolis ( Plovdiv, Bulgaria ) or Sirmium, Diocletian would do the same for Galerius, husband to Diocletian's daughter Valeria, and perhaps Diocletian's praetorian prefect.

Galerius was assigned Syria, Palestine, Egypt, and responsibility for the eastern borderlands.

The senior co-Emperors formally adopted Galerius and Constantius as sons in 293.

Galerius and Constantius would become Augusti after Diocletian and Maximian's departure.

Afterwards, during 299 and 302, as Diocletian was then residing in the East, it was Galerius ' turn to campaign victoriously on the Danube.

Galerius, meanwhile, was engaged during 291 – 293 in disputes in Upper Egypt, where he suppressed a regional uprising.

Diocletian's attempts to bring the Egyptian tax system in line with Imperial standards stirred discontent, and a revolt swept the region after Galerius ' departure.

He met up with Galerius in Mesopotamia.

In a public ceremony at Antioch, the official version of events was clear: Galerius was responsible for the defeat ; Diocletian was not.

Diocletian publicly humiliated Galerius, forcing him to walk for a mile at the head of the Imperial caravan, still clad in the purple robes of the Emperor.

Galerius was reinforced, probably in the spring of 298, by a new contingent 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.

Narseh retreated to Armenia to fight Galerius ' force, to Narseh's disadvantage ; the rugged Armenian terrain was favorable to Roman infantry, but unfavorable to Sassanid cavalry.

In two battles, Galerius won major victories over Narseh.

Galerius continued moving down the Tigris, and took the Persian capital Ctesiphon before returning to Roman territory along the Euphrates.

Narseh sent an ambassador to Galerius to plead for the return of his wives and children in the course of the war, but Galerius had dismissed him.

Diocletian and Galerius ' magister memoriae ( secretary ) Sicorius Probus were sent to Narseh to present terms.

At the conclusion of the peace, Diocletian and Galerius returned to Syrian Antioch.

Diocletian was conservative in matters of religion, a man faithful to the traditional Roman pantheon and understanding of demands for religious purification, but Eusebius, Lactantius and Constantine state that it was Galerius, not Diocletian, who was the prime supporter of the purge, and its greatest beneficiary.

Galerius, even more devoted and passionate than Diocletian, saw political advantage in the politics of persecution.