Danube basin in the context of "Pannonian Avars"

The Pannonian Avars (/ˈævɑːrz/ AV-arz) were an alliance of several groups of Eurasian nomads of various origins. The peoples were also known as the Obri (modern Russian: обры, Obry) in the chronicles of the Rus, the Abaroi or Varchonitai (Greek: Βαρχονῖται, romanized: Varchonitai), or Pseudo-Avars in Byzantine sources, and the Apar (Old Turkic: 𐰯𐰺) to the Göktürks. They established the Avar Khaganate, which spanned the Pannonian Basin and considerable areas of Central and Eastern Europe from the late-6th to the early-9th centuries.

The name "Pannonian Avars" (after Pannonia in the upper Danube basin where they eventually settled) is used to distinguish them from the Avars of the Caucasus, a separate people with whom the Pannonian Avars may or may not have had links. Although the name Avar first appeared in the mid-5th century, the Pannonian Avars entered the historical scene in the mid-6th century, on the Pontic–Caspian steppe as a people who wished to escape the rule of the Göktürks. They are probably best known for their invasions and destruction in the Avar–Byzantine wars from 568 to 626 and for their influence on the Slavic migrations to the Balkans.

The Danubian provinces of the Roman Empire were the provinces of the Lower Danube, within a geographical area encompassing the middle and lower Danube basins, the Eastern Alps, the Dinarides, and the Balkans. They include Noricum, Dacia (Trajana and Aureliana), the northern part of Dalmatia, Moesia (Inferior and Superior), Scythia Minor, and Pannonia (Superior and Inferior). The Danube defined the region to the north, with the Carpathian Mountains to the north and east. These provinces were important to the Imperial economy as mining regions, and their general significance in the Empire of the 3rd century is indicated by the emperors who came from the region.

The Roman presence in the region can be described as having four phases from Augustus to Hadrian: military conquest under Augustus, and consequent military actions; the establishment of military bases along roads and river crossings under Claudius; the establishment of camps along the river for stationing legions and auxiliaries carried out by the Flavian dynasty and Trajan; and further expansion into Dacia north of the Danube. Hadrian's approach was to defend and maintain, a policy that remained more or less in effect until the latter 4th century, when Roman control disintegrated. The pattern of Roman settlement after the time of Hadrian became standard: a fort (castra), a military town (canabae) associated with it, and a town (municipium) developing two or three miles away.