The
Odrysian kingdom of Thrace became a Roman
client kingdom c. 20 BC, while the Greek
city-states on the
Black Sea coast came under Roman control as
civitates foederatae ("allied" cities with internal autonomy). After the death of the Thracian king
Rhoemetalces III in 46 AD and an unsuccessful anti-Roman revolt, the kingdom was annexed as the
Roman province of Thracia. The new province encompassed not only the lands of the former Odrysian realm, but also the north-eastern portion of the province of
Macedonia as well as the islands of
Thasos,
Samothrace and
Imbros in the
Aegean Sea. To the north, Thracia bordered the province of
Moesia Inferior; initially, the provincial boundary ran at a line north of the
Haeumus Mountains, including the cities of
Nicopolis ad Istrum and
Marcianopolis in Thracia, but by the end of the 2nd century AD the border had moved south along the Haemus. The area of the
Thracian Chersonese (modern
Gallipoli Peninsula) was excluded from its governor's purview and administered as part of the emperor's personal domains. The province's first capital, where the Roman governor resided, was
Heraclea Perinthus. Thracia was an
imperial province, headed initially by a
procurator, and, after c. 107/109, by a
legatus Augusti pro praetore. Otherwise, the internal structure of the old Thracian kingdom was retained and only gradually superseded by Roman institutions. The old tribal-based
strategiai ("generalcies"), headed by a
strategos ("general"), were retained as the main administrative divisions, but some villages were grouped together into
kōmarchiai ("village headships") or subordinated to neighbouring cities (the two
Roman colonies of
colonia Claudia Aprensis and
colonia Flavia Pacis Deueltensium and several Greek cities, many of whom were founded by
Trajan), which were set apart. In the mid-1st century, the
strategiai numbered fifty, but the progressive expansion of the cities and the land assigned to them reduced their number: by the early 2nd century, they had decreased to fourteen, and c. 136 they were abolished altogether as official administrative divisions.
Septimius Severus (r. 193–211), frequently traveled through Thrace during his military campaigns from 193 to 198, first during his war with
Pescennius Niger and later against the
Parthians. The city of
Perinthus, which backed Severus, was granted the prestigious title of
neokoros twice, alongside the permission to hold crown festivals in his honor. Severus also allowed
Anchialus to organize
seuereia festivals, possibly as a reward for its support during the civil war. As it was an interior province, far from the borders of the Empire, and having a major Roman road (
Via Egnatia) that passed through the region, Thrace remained peaceful and prosperous until the
Crisis of the Third Century, when it was repeatedly raided by
Goths from beyond the
Danube. During the campaigns to confront these raiders, Emperor
Decius (r. 249–251) fell in the
Battle of Abritus in 251. Thracia suffered especially heavily in the great
Gothic seaborne raids of 268–270, and it was not until 271 that Emperor
Aurelian (r. 270–275) was able to secure the Balkan provinces against Gothic raids for some time to come. Generally, the provincial and urban policy of Roman emperors, with the foundation of several cities of Greek type (city-state), contributed more to the progress of Hellenization than to the Romanization of Thrace. So by the end of Roman antiquity, the phenomenon of Romanization occurs only upon the Lower Moesia, while Thrace lying south of the Haemus mountains had been almost completely Hellenized. As regards the Thracian dispersion outside the borders (
extra fines provinciae), from epigraphic evidence we know the presence of many Thracians (mostly soldiers) throughout the Roman Empire from Syria and Arabia to Britain. == Late antiquity ==