* 308 – At Carnuntum, Emperor emeritus Diocletian confers with Galerius, Augustus of the East, and Maximianus, the recently returned former Augustus of the West, in an attempt to restore order to the Roman Empire.

When the Roman Empire was divided into the tetrarchy, Thessaloniki became the administrative capital of one of the four portions of the Empire under Galerius Maximianus Caesar, where Galerius commissioned an imperial palace, a new hippodrome, a triumphal arch and a mausoleum among others.

* Gaius Galerius Valerius Maximianus, Roman Emperor ( d. 311 )

* May 5 – Gaius Galerius Valerius Maximianus, Roman emperor

The Late Roman fortified palace compound and memorial complex of Gamzigrad-Romuliana at the outskirts of Zaječar was commissioned by Emperor Caius Valerius Galerius Maximianus, in the late 3rd and early 4th century.

“ Brass Medallion Representing the Persian Victory of Maximianus Galerius .”/

An alternative explanation, that the province was named after Galerius Maximianus, emperor of the east, would have to account for an eastern emperor's being honoured, while the two Augusti of the Tetrachy were not.

** Caesar: Galerius (" Galerius Valerius Maximianus Nob.

Caesar "; b. Galerius Valerius Maximianus ), 293 – 305

Caesar Galerius Valerius Maximianus P. F.

Invictus Aug ."; b. Galerius Valerius Maximianus ), 305 – 311

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.

* Adrian of Nicomedia ( died 306 ), martyr and Herculian Guard of the Roman Emperor Galerius Maximian

Narseh moved south into Roman Mesopotamia in 297, where he inflicted a severe defeat on Galerius in the region between Carrhae ( Harran, Turkey ) and Callinicum ( Ar-Raqqah, Syria ) ( and thus, the historian Fergus Millar notes, probably somewhere on the Balikh River ).

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.

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

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.

* 293 – Roman Emperors Diocletian and Maximian appoint Galerius as Caesar to Diocletian, beginning the period of four rulers known as the Tetrarchy.

* Adrian of Nicomedia ( died 306 ), Herculian Guard of the Roman Emperor Galerius Maximian

After suffering a defeat by the Persians in 296, Galerius crushed Narseh in 298 — reversing a series of Roman defeats throughout the century — capturing members of the imperial household and a substantial amount of booty and gaining a highly favourable peace treaty, which secured peace between the two powers for a generation.

The first book sketches briefly the history of the early Roman emperors from Augustus to Diocletian ( 305 ); the second, third and fourth deal more fully with the period from the accession of Constantius Chlorus and Galerius to the death of Theodosius I ; the fifth and sixth, the most useful for historians, cover the period between 395 and 410, when Priscus Attalus was deposed ; for this period, he is the most important surviving non-ecclesiastical source.

* A number of Roman emperors of the 3rd-5th century were of Thraco-Roman backgrounds ( Maximinus Thrax, Licinius, Galerius, Aureolus, Leo the Thracian, etc .).

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.

* Galerius, Roman Caesar in the Balkan, is dispatched to Egypt to fight against the rebellious cities Busiris and Coptos.

* Galerius, Roman Caesar in the Balkan, proves his worth in campaigning on the Danube frontier, fighting the Goths, Marcomanni, Sarmatians, and Carpi.

* Galerius is given the unspectacular job of land reclamation and repopulation, moving the entire tribe of the Carpi to settlements within the Roman Empire.

* Galerius, Roman Emperor ( approximate date )

* Galerius grants Constantine I the title Caesar and elevates Severus II to co-emperor of the Western Roman Empire.

* May 5 – Emperor Galerius declares on his deathbed religious freedom and issues his Edict of Toleration, ending persecution of Christians in the Eastern part of the Roman Empire.

* Emperor Jovian negotiates a disastrous peace with Persia, surrendering four of the five Roman provinces gained by Caesar Galerius in 298, and the cities Nisibis and Singara ( Mesopotamia ).

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 ).

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.

In 308 Galerius, together with the retired emperor Diocletian and the supposedly retired Maximian, called an imperial " conference " at Carnuntum on the River Danube.

In 295, emperor Galerius was defeated outside the city.

Constantine I, age 26, is declared Augustus ( emperor ) by his troops and awaits recognition by Emperor Galerius.

But whereas Constantine's claim was recognized by Galerius, ruler of the Eastern provinces and the senior emperor in the empire, Maxentius was treated as a usurper.

Galerius sent his subordinate emperor, Severus, against him in early 307.

Constantius, notionally the senior emperor, ruled the western provinces, while Galerius took the eastern provinces.

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.

Born to a Dacian peasant family in Moesia Superior, Licinius accompanied his close childhood friend, the future emperor Galerius, on the Persian expedition in 298.

It was said that he had put to death Severianus, the son of the emperor Severus, as well as Candidianus, the son of Galerius.

He was born of Dacian peasant stock to the half sister of the emperor Galerius near their family lands around Felix Romuliana ; a rural area then in the Danubian region of Moesia, now Eastern Serbia.

When Constantius died in 306, his son Constantine was crowned emperor on July 25 and subsequently accepted by Galerius into the tetrarchy as Caesar.

Maxentius refrained from using the titles Augustus or Caesar at first and styled himself princeps invictus ( Undefeated Prince ), in the hope of obtaining recognition of his reign by the senior emperor Galerius.

Constantine firmly controlled his father's army and territories, and Galerius could pretend that his accession was part of the regular succession in the tetrarchy, but neither was the case with Maxentius: he would be the fifth emperor, and he had only few troops at his command.

The emperor Galerius was defeated nearby by the Parthians ' successors, the Sassanid dynasty of Persia, in 296 CE.

He rose to become a senior officer in the Roman army, and as an old friend of Galerius, that emperor ordered that Severus be appointed Caesar of the Western Roman Empire, a post that he succeeded to on 1 May 305.

When Maxentius, the son of the retired emperor Maximian, revolted at Rome, Galerius sent Severus to suppress the rebellion.

* Claudius Eusthenius, secretary to the emperor Diocletian, he wrote lives of Diocletian, Maximian, Galerius, and Constantius.

During the tetrarchy, Sirmium was the capital of emperor Galerius.

* Galerius, Roman emperor ( 305-311 ), ruled as Caesar during the Tetrarchy from residence in Sirmium ( 293-296 ).

A previous edict of toleration had been recently issued by the emperor Galerius from Serdica and posted up at Nicomedia on 30 April 311.

Having received the emperor Galerius ' instruction to repeal the persecution in 311, Maximinus had instructed his subordinates to desist, but had not released Christians from prisons or virtual death-sentences in the mines, as Constantine and Licinius had both done in the West.

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.