Diocese of Thrace in the context of "Scythia Minor (Roman province)"

Thracia or Thrace (Ancient Greek: Θρᾴκη, romanized: Thrakē) is the ancient name given to the southeastern Balkan region, the land inhabited by the Thracians. Thrace was ruled by the Odrysian kingdom during the Classical and Hellenistic eras, and briefly by the Greek Diadochi ruler Lysimachus, but became a client state of the late Roman Republic and early Roman Empire as the Sapaean kingdom. Roman emperor Claudius annexed the kingdom as a Roman province in 46 AD.

The praetorian prefecture of Illyricum (Latin: praefectura praetorio per Illyricum; Greek: ὑπαρχία τῶν πραιτωρίων τοῦ Ἰλλυρικοῦ, also termed the prefecture of Illyricum) was one of four praetorian prefectures into which the Late Roman Empire was divided.

The administrative center of the prefecture was Sirmium from 375 to 379, then Thessalonica. The prefecture took its name from the older province of Illyricum, which in turn was named after ancient Illyria. In its greatest expanse it encompassed Pannonia, Noricum, Crete, and most of the Balkan peninsula except for Thrace.

The Antes or Antae (Greek: Ἄνται) were an early Slavic tribal polity of the 6th century CE. They lived on the lower Danube River, in the northwestern Black Sea region (present-day Moldova and central Ukraine), and in the regions around the Don River (in Middle and Southern Russia). Scholars commonly associate the Antes with the archaeological Penkovka culture.

First mentioned in the historical record in 518, the Antes invaded the Eastern Roman Empire in the area of the Diocese of Thrace sometime between the years of 533 and 545. Thereafter, they became Byzantine foederati and received gold payments and a fort (named "Turris" – the Latin word turris means 'tower') somewhere north of the Danube at a strategically important location to prevent hostile barbarians from invading Roman lands. Thus from 545 to the 580s, Antean soldiers fought in various Byzantine campaigns. The Pannonian Avars, the Bulgars and the Khazars attacked the Antes in the 7th century, causing disappearance of the Antes as a group and of the Penkovka culture phenomenon.

Scythia Minor or Lesser Scythia (Greek: Μικρά Σκυθία, romanized: Mikra Skythia) was a Roman province in late Antiquity, occupying the lands between the lower Danube and the Black Sea, the modern-day Dobruja region in Romania and Bulgaria. It was detached from Moesia Inferior by the Emperor Diocletian to form a separate province sometime between 286 and 293 CE. The capital of the province was Tomis (modern-day Constanța). It ceased to exist around 679–681, when the region was overrun by the Bulgars, which the Emperor Constantine IV was forced to recognize in 681.

According to the Laterculus Veronensis of c. 314 and the Notitia Dignitatum of c. 400, Scythia belonged to the Diocese of Thrace. Its governor held the title of praeses and its dux commanded two legions, Legio I Iovia and Legio II Herculia. The office of dux was replaced by that of quaestor exercitus, covering a wider area, in 536.

The Theme of Macedonia (Greek: θέμα Μακεδονίας théma Makedonías) was a military-civilian province (theme) of the Byzantine Empire established between the late 8th century and the early 9th century. The theme of Macedonia had limited geographical relation to the previous province of Macedonia and mainly lay in the southwestern parts of what previously was the adjacent Diocese of Thrace. Its capital was Adrianople.

Rhodope (Greek: Ῥοδόπη) was a late Roman and early Byzantine province, situated on the northern Aegean coast. A part of the Diocese of Thrace, it extended along the Rhodope Mountains range, covering parts of modern Western Thrace (in Greece) and south-western Bulgaria. The province was headed by a governor of the rank of praeses, with Trajanopolis as the provincial capital. According to the 6th-century Synecdemus, there were six further cities in the province, Maroneia, Maximianopolis, Nicopolis, Kereopyrgos (unknown location) and Topeiros (mod. Toxotai in Greece).

The province survived until the Slavic invasions of the 7th century, although as an ecclesiastic province, it continued in existence at least until the 12th century. The theme of Boleron covered most of the area in later Byzantine times.