…Thessalonica, transformed from Therma, as well as …

…Thessaloniki.

The Gothic army moves north, assaulting the wealthy Macedonian capital at Salonika.

Constantine prevails again against his Eastern counterpart Licinius (shortly after he had named as co-emperor Valerius Valens, who had previously been dux limitis in Dacia) in the plain of Mardia (also known as Campus Ardiensis) in Thrace.

The emperors are reconciled after this battle.

Licinius according to a peace signed on March 1, 317, has to execute Valerius Valens, and cedes territory to Constantine, including …

Licinius has been exiled to Thessalonica under a kind of house arrest, but when he attempts to raise troops among the barbarians, Constantine has him assassinated, together with his former co-emperor Sextus Martinianus, on a charge of attempted rebellion, undermining a promise the emperor had made half a year earlier.

Emperor Theodosius, residing chiefly in Thessalonica, seeks first to rebuild the imperial army, the discipline of which is considerably impaired, and to consolidate Rome's position on the Balkan peninsula.

Military unpreparedness cannot be overcome by conscription alone, which applies only to certain classes.

Theodosius therefore directs that the army accept large numbers of Germans, who had been barred from military service.

Foreigners have by 379, however, already intermingled extensively with the rest of the army, both among the troops and in all ranks of the officer corps, so Theodosius does no more than many of his predecessors to encourage this process.

Both Romans and Germans are among the leading generals in Theodosius' provinces, in contrast to the West.

Theodosius' situation is complicated by the sharp antagonism that arises around 379 between disciples of the Nicene Creed (according to which Jesus Christ is of the same substance as God the Father) and several other Christian groups in his part of the empire.

The Christian Church has become synonymous with the Roman Empire by about 380 , but Theodosius finds his realm divided between rival orthodox and Arian Christian groups.

Propelled by political as well as religious motives, he energetically undertakes to bring about unity of faith within the empire.

Soon dominating his weak colleague, Theodosius enters the battle on the side of orthodoxy, becoming the first emperor who does not assume the title of pontifex maximus (supreme guardian of the old Roman cults).

His position has been improved by the fact that during 379 the followers of the Nicene Creed had gained ground, whereupon Theodosius, without consulting the ecclesiastical authorities, issues an edict on February 28, 380, prescribing a creed that is to be binding on all subjects.

Only persons who believe in the consubstantiality of God the Father, Son, and Holy Spirit are henceforth to be considered Catholic Christians, a designation that here appears for the first time in a document.

Although Theodosius’ belief in the Nicene Creed is apparently genuine, he submits to baptism in the fall of 380 only after a serious illness.

Theodosius, to safeguard Greece after a series of raids by the Goths, had stationed a large number of troops under General Butheric in Thessalonika, a city that had never been a garrison town.

The Thessalonians resent having to maintain the army, and tensions mount as quarrels between the soldiers and the citizens increase in number.

The trouble comes to a head in the summer of 390 when a popular charioteer makes a sexual advance to one of Butheric's attendants.

The general, taking the incident as a personal insult, has the charioteer thrown into prison.

When a mob gathers to protest the confinement of one of their favorite athletes, the demonstration degenerates into a riot in which Butheric is killed.

In retaliation for the murder of his general, Theodosius looses his troops on the city, making no attempt to sort the guilty from the innocent.

In the space of only three hours, seven thousand men, women, and children are massacred.

The Slavs are meanwhile pouring into Thrace, Thessaly, Illyricum, and other regions of Greece.

Slavic tribes in 582 attempt to capture Thessaloniki, and settle around it.

The Slavs invade the area around Thessaloniki, which they besiege unsuccessfully.

The city becomes an imperial Greek enclave surrounded by Slavic territory.

Urban life disappears and many towns in the Balkan Peninsula become villages.