Battle of Adrianople in the context of "Goths"

Theodosius I (Ancient Greek: Θεοδόσιος Theodosios; 11 January 347 – 17 January 395), also known as Theodosius the Great, was Roman emperor from 379 to 395. He won two civil wars and was instrumental in establishing the Nicene Creed as the orthodox doctrine for Nicene Christianity. Theodosius was the last emperor to rule the entire Roman Empire before its administration was permanently split between the Western Roman Empire and the Eastern Roman Empire. He ended the Gothic War (376–382), but did so on terms disadvantageous to the empire, with the Goths remaining and politically autonomous within Roman territory, albeit as nominal allies.

Born in Hispania, Theodosius was the son of a high-ranking general of the same name, Theodosius the Elder, under whose guidance he rose through the ranks of the Roman army. Theodosius held independent command in Moesia in 374, where he had some success against the invading Sarmatians. Not long afterwards, he was forced into retirement, and his father was executed under obscure circumstances. Theodosius soon regained his position following a series of intrigues and executions at Emperor Gratian's court. In 379, after the eastern Roman emperor Valens was killed at the Battle of Adrianople against the Goths, Gratian appointed Theodosius as a successor with orders to take charge of the military emergency. The new emperor's resources and depleted armies were not sufficient to drive the invaders out; in 382 the Goths were allowed to settle south of the Danube as autonomous allies of the empire. In 386, Theodosius signed a treaty with the Sasanian Empire which partitioned the long-disputed Kingdom of Armenia and secured a durable peace between the two powers.

The Visigoths (/ˈvɪzɪɡɒθs/; Latin: Visigothi, Wisigothi, Vesi, Visi, Wesi, Wisi) were a Gothic people who emerged in the Balkans during late antiquity. Likely descended from the Thervingi who entered the Roman Empire in 376 and defeated the Romans at the Battle of Adrianople (378), they were first united under Alaric I (395–410), whose forces alternately fought and allied with Rome before famously sacking the city in 410.

In 418, the Visigoths were settled as foederati in southern Gaul, establishing a kingdom with its capital at Toulouse. From there they expanded into Hispania, displacing the Suebi and Vandals. Defeat by the Franks under Clovis I at the Battle of Vouillé (507) ended Visigothic rule in Gaul, but the kingdom consolidated in Spain and Portugal, where it endured for two centuries.

Alaric I (/ˈælərɪk/; Gothic: 𐌰𐌻𐌰𐍂𐌴𐌹𐌺𐍃, Alarīks lit.'ruler of all'; Latin: Alaricus; c. 370 – 411 AD) was the first king of the Visigoths, from 395 to 410. He rose to leadership of the Goths who came to occupy Moesia—territory acquired a couple of decades earlier by a combined force of Goths and Alans after the Battle of Adrianople.

Alaric began his career under the Gothic soldier Gainas and later joined the Roman army. Once an ally of Rome under the Roman emperor Theodosius, Alaric helped defeat the Franks and other allies of a would-be Roman usurper. Despite losing many thousands of his men, he received little recognition from Rome and left the Roman army disappointed. After the death of Theodosius and the disintegration of the Roman armies in 395, he is described as king of the Visigoths. As the leader of the only effective field force remaining in the Balkans, he sought Roman legitimacy, never quite achieving a position acceptable to himself or to the Roman authorities.

The Gothic War of 376–382 was one of several Gothic Wars in Roman history in which the Goths fought against the Roman Empire. This particular conflict included the catastrophic Roman defeat at the Battle of Adrianople, which is commonly seen as a cause of the decline of the Western Roman Empire, although its significance is widely debated.

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.

Ammianus Marcellinus, occasionally anglicized as Ammian (Greek: Αμμιανός Μαρκελλίνος; born c. 330, died c. 391 – 400), was a Greek and Roman soldier and historian who wrote the penultimate major historical account surviving from antiquity (preceding Procopius). Written in Latin and known as the Res gestae, his work chronicled the history of Rome from the accession of Emperor Nerva in 96 to the death of Valens at the Battle of Adrianople in 378. Only the sections covering the period 353 to 378 survive.

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.