Valentinian I in the context of "Count Theodosius"

Niš (/ˈniːʃ/; Serbian Cyrillic: Ниш, Serbian pronunciation: [nîːʃ] ; names in other languages), less often spelled in English as Nish, is the third largest city in Serbia and the administrative center of the Nišava District. It is located in the southern part of Serbia. According to the 2022 census, the city proper has a population of 178,976, while its administrative area has a population of 249,501 inhabitants.

Several Roman emperors were born in Niš or used it as a residence: Constantine the Great, the first Christian emperor and the founder of Constantinople, Constantius III, Constans, Vetranio, Julian, Valentinian I, Valens; and Justin I. Emperor Claudius Gothicus decisively defeated the Goths at the Battle of Naissus (present-day Niš). Later playing a prominent role in the history of the Byzantine Empire, the city's past would earn it the nickname Imperial City.

Count Theodosius (Latin: Theodosius comes; died 376), Flavius Theodosius or Theodosius the Elder (Latin: Theodosius major), was a senior military officer serving Valentinian I (r. 364–375) and the Western Roman Empire during Late Antiquity. Under his command the Roman army defeated numerous threats, incursions, and usurpations. Theodosius was patriarch of the imperial Theodosian dynasty (r. 379–457) and father of the emperor Theodosius the Great (r. 379–395).

Appointed comes rei militaris per Britannias (commander of mobile military forces for the Diocese of the Britains) by Valentinian, Theodosius put down the Great Conspiracy (367–368) and the usurpation of Valentinus. After restoring order in Britain he returned to continental Europe and fought against the Alemanni; as Valentinian's magister equitum (Master of Horse) he successfully invaded Alemannic territory (371 or 370). In 372 Theodosius led a successful campaign against the Sarmatians. Within the same year Firmus, a Mauritanian prince, rebelled against Roman rule with the help of African tribes like the Abanni and Caprarienses. Theodosius was sent to Africa and in two hard-fought campaigns (373–374) put down the insurrection. In 376, after the death of emperor Valentinian, he was arrested and executed, presumably as he was seen as a threat to the new western emperors Gratian and Valentinian II.

Gratian (/ˈɡreɪʃiən/; Latin: Gratianus; 18 April 359 – 25 August 383) was emperor of the Western Roman Empire from 367 to 383. The eldest son of Valentinian I, Gratian was raised to the rank of Augustus as a child and inherited the West after his father's death in 375. He nominally shared the government with his infant half-brother Valentinian II, who was also acclaimed emperor in Pannonia on Valentinian's death. The East was ruled by his uncle Valens, who was later succeeded by Theodosius I.

Gratian subsequently led a campaign across the Rhine, attacked the Lentienses, and forced the tribe to surrender. That same year, the eastern emperor Valens was killed fighting the Goths at the Battle of Adrianople, which led to Gratian elevating Theodosius to replace him in 379. Gratian favoured Nicene Christianity over traditional Roman religion, issuing the Edict of Thessalonica, refusing the office of pontifex maximus, and removing the Altar of Victory from the Roman Senate's Curia Julia. The city of Cularo on the Isère river in Roman Gaul was renamed Gratianopolis after him, which later evolved to Grenoble. By 383 Gratian had become unpopular with his army, which abandoned him during a confrontation with the usurper Magnus Maximus near Lutetia (Paris). Gratian fled to Lugdunum and was later murdered.

Valens (/ˈveɪlənz/; Ancient Greek: Ουάλης, romanized: Ouálēs; 328 – 9 August 378) was Roman emperor from 364 to 378. Following a largely unremarkable military career, he was named co-emperor by his elder brother Valentinian I, who gave him the eastern half of the Roman Empire to rule. In 378, Valens was defeated and killed at the Battle of Adrianople against the invading Goths, which astonished contemporaries and marked the beginning of barbarian encroachment into Roman territory.

As emperor, Valens continually faced threats both internal and external. He defeated, after some dithering, the usurper Procopius in 366, and campaigned against the Goths across the Danube in 367 and 369. In the following years, Valens focused on the eastern frontier, where he faced the perennial threat of Persia, particularly in Armenia, as well as additional conflicts with the Saracens and Isaurians. Domestically, he inaugurated the Aqueduct of Valens in Constantinople, which was longer than all the aqueducts of Rome. In 376–77, the Gothic War broke out, following a mismanaged attempt to settle the Goths in the Balkans. Valens returned from the east to fight the Goths in person, but lack of coordination with his nephew, the western emperor Gratian (Valentinian I's son), as well as poor battle tactics, led to Valens and much of the eastern Roman army dying in a battle near Adrianople in 378.

The Valentinian dynasty, commonly known as the Valentinianic dynasty, was a ruling house of five generations of dynasts, including five Roman emperors during late antiquity, lasting nearly a hundred years from the mid fourth to the mid fifth century. They succeeded the Constantinian dynasty (r. 306–363) and reigned over the Roman Empire from 364 to 392 and from 425 to 455, with an interregnum (392–425), during which the Theodosian dynasty ruled and eventually succeeded them. The Theodosians, who intermarried into the Valentinian house, ruled concurrently in the east after 379.

The Valentinian dynasty's patriarch was Gratianus Funarius, whose sons Valentinian I and Valens were both made Roman emperors in 364. Valentinian I's two sons, Gratian and Valentinian II both became emperors. Valentinian I's daughter Galla married Theodosius the Great, the emperor of the eastern empire, who with his descendants formed the Theodosian dynasty (r. 379–457). In turn, their daughter, Galla Placidia married a later emperor, Constantius III (r. 421–421). Their son, Valentinian III (r. 425–455), who ruled in the west, was the last emperor of the dynasty, whose death marked the end of dynasties in the western empire. During the interregnum, Theodosius' son Honorius ruled in the west, and concurrently with Constantius III in 421. The dynasty has been labelled as Pannonian, based on the family origin in Pannonia Secunda in the western Balkans.

Valentinus (fl. mid-4th century, died 369) was a Roman criminal and rebel put down after Count Theodosius's arrival in Britain in AD 369.

Ammianus Marcellinus records that Valentinus was a Pannonian whose brother-in-law Maximinus was close to the emperor Valentinian I. Having committed some serious crime, he was able to have his sentence commuted to exile to Britain, where he resided at the time of the Great Conspiracy. Ammianus does not record that Valentinus took part in that barbarian rising, but does claim that he began planning a new revolt after the arrival of Theodosius. He organized fellow exiles and attempted to bribe local troops to his cause. Discovered, he was given over to Duke Dulcitius for execution, but Ammianus notes that investigation into Valentinus's plot was cursory, lest it produce more unrest in the province.

Firmus (died 375) was a Berber Numidian prince and Roman usurper under Valentinian I.

Firmus was the son of the Berber Jubaleni prince Nubel, a powerful Roman military officer, as well as a wealthy Christian. When Nubel died, Firmus killed his half-brother Zammac, who had illegitimately appropriated Nubel's wealth, and became successor to his father.

The Abanni (also called Abannae) were an ancient tribe in the northwest of Africa.

They settled in the ancient region of Mauretania, which encompassed the north of the present-day states of Morocco and Algeria and was part of the Roman Empire in the first centuries anno Domini. Together with the adjacent tribe of the Caprarienses, whose members lived in the mountains named after them, the Abanni in circa 375 AD took part in the uprising of the usurper Firmus against the Roman Emperor Valentinian I. Both tribes were defeated by the Roman general Theodosius. After this success Theodosius is believed to have subsequently moved to Auzia.

Valentinian II (Latin: Valentinianus; 371 – 15 May 392) was a Roman emperor in the western part of the Roman Empire between AD 375 and 392. He was at first junior co-ruler of his half-brother, then was sidelined by a usurper, and finally became sole ruler after 388, albeit with limited de facto powers. He was the youngest emperor (co-ruler) in the Western Roman Empire (aged 4).

A son of emperor Valentinian I and empress Justina, he was raised to the imperial office at the age of four by military commanders upon his father's death. Until 383, Valentinian II remained a junior partner to his older half-brother Gratian in ruling the Western empire, while the East was governed by his uncle Valens until 378 and Theodosius I from 379. When the usurper emperor Magnus Maximus killed Gratian in 383, the court of Valentinian II in Milan became the locus of confrontations between adherents to Nicene and Arian Christianity. In 387, Maximus invaded Italy, spurring Valentinian II and his family to escape to Thessalonica where they successfully sought Theodosius's aid. Theodosius defeated Maximus in battle and re-installed Valentinian II.