Legio X Equestris had been one of the four legions used by Julius Caesar in 58 BCE, for his invasion of Gaul.

They had remained faithful to Caesar in the civil war against Pompey, being present in the battles of Pharsalus (49 BCE) and Munda (45 BCE).

In 45 BCE, Caesar had disbanded the legion, giving the veterans farmlands near Narbonne.

The legion had been reconstituted in 42 BCE and fought for Augustus (then Octavian), Lepidus and Mark Antony in the Battle of Philippi against the murderers of Caesar.

After this, they had followed Mark Antony in his campaign against Parthia and were defeated with him at Actium.

Augustus then took control of the legion and settled the veterans in Patras.

The legion rebelled and lost its cognomen Equestris as punishment.

Reinforcements had been added from other legions, and the Tenth was rebaptized Gemina.

The newly formed X Gemina had been relocated to Hispania Tarraconensis, where Augustus was preparing a campaign against the Cantabrians.

They stayed in Hispania for many years and their veterans were among the first inhabitants of modern Zaragoza.

In 70, after the Batavian rebellion had been suppressed by Vespasian, X Gemina was sent to Batavia in Germania Inferior to police the lands and prevent new revolts.

From 71 to 103, the legion has been stationed at the base built by II Adiutrix at Oppidum Batavorum, the present day Dutch city of Nijmegen.

As part of the army of Germania Inferior, X Gemina had fought against the rebellion of the governor of Germania Superior, L. Antonius Saturninus, against Emperor Domitian.

For this reason, the Tenth — as well as the other legions of the army, I Minervia, VI Victrix, and XXII Primigenia — had received the title Pia Fidelis Domitiana, "faithful and loyal to Domitian", with the reference to the Emperor dropped at his death.

In 103, it is moved to Aquincum and later to …

Operations continue against the Iazyges, the Buri and the so-called "free Dacians" living between the Danube and Roman Dacia.

Not much is known about this war, except that the Roman generals include Marcus Valerius Maximianus, and the future usurpers Pescennius Niger and Clodius Albinus.

At any rate, the victories they achieve are deemed sufficient for Commodus to claim the title "Germanicus Maximus" in mid-182.

The Pannonian army at Aquincum (near modern Budapest), rife with intrigue, five days after the emperor's death declares Gratian's four-year-old half-brother Valentinian, the offspring of the emperor's second wife, Justina, Emperor Valentinian II.

The declaration is made without the knowledge or consent of the two reigning emperors, Valens and Gratian, but they soon accept Valentinian and allow him to rule Illyricum through Justina.

The Hasdingi, the larger of the two branches of Vandals, had already been Christianized during the first half of the fourth century.

During the reign of Emperor Valens (364–78) the Vandals had accepted, much like the Goths earlier, Arianism, a belief that was in opposition to that of Nicene orthodoxy of the Roman Empire.

Yet there are also some scattered orthodox Vandals, among whom is the famous magister militum Stilicho, the chief minister of the Emperor Honorius.

Khan Kubrat of the Great Bulgaria had quickly managed to overthrow Avar domination—if it had not already been achieved by his predecessors in alliance with first Constantinople, then Samo and the Slavs of whom he is king—thus extending Onogur influence among the Bulgarians in Pannonia in what will subsequently become known as Hungary.

A revolt within the Avar Empire, precipitated by the creation in the second half of the seventh century of the Bulgarian state in the southeastern Balkans, results in the expulsion of about nine thousand dissidents.

The name Onogur is most often analyzed as On-Oğuz "ten (tribes of the) Oğuz".

In older "Oghur" Turkic languages, On~Ono means "ten" and Gar~Gurs~Gur means "tribes", so Onogurs means "People of ten tribes".

Alternative suggestions have connected the Onogurs with the polity of the Western Turkic Kaghanate as the "People of Ten Arrows" (On-oq-ar), the Utigurs, and the Adygers.

The name of Hungary and the name of the Hungarian people are also connected with the term Hunuguria/Onoguria/Unoguria, because in the western European languages the Hungarians (Magyars) are called Onogurs (e.g., Ungarn, Hongrie, Hongar, Ungherese).

The Magyars are said to have belonged to the Onogur tribal alliance.

According to the Chronicon Pictum, a medieval illustrated chronicle from the Kingdom of Hungary from the fourteenth century, the last of the Onogur tribes fleeing Khazars in the Ukraine come to Hrpad in Pannonia and the area becomes known as Hungary (but not yet Magyarorszag).