Romans began to directly appoint their kings. This situation lasted until 46 AD, when the Romans finally turned Thrace into a Roman province (Romana provincia Thracia). During the Roman domination, within the geographical borders of ancient Thrace, there were two separate Roman provinces, namely Thrace ("provincia Thracia") and Lower Moesia ("Moesia inferior"). Later, in the times of Diocletian, the two provinces were joined and formed the so-called "Dioecesis Thracia". The establishment of Roman colonies and mostly several Greek cities, as was Nicopolis, Topeiros, Traianoupolis, Plotinoupolis, and Hadrianoupolis resulted from the Roman Empire's urbanization. The Roman provincial policy in Thrace favored mainly not the Romanization but the Hellenization of the country, which had started as early as the Archaic period through the Greek colonisation and was completed by the end of Roman antiquity. As regards the competition between the Greek and Latin language, the very high rate of Greek inscriptions in Thrace extending south of Haemus Mountains proves the complete language Hellenization of this region. The boundaries between the Greek and Latin speaking Thrace are placed just above the northern foothills of Haemus Mountains. During the imperial period many Thracians – particularly members of the local aristocracy of the cities – had been granted the right of the Roman citizenship (civitas Romana) with all its privileges. Epigraphic evidence show a large increase in such naturalizations in the times of Trajan and Hadrian, while in 212 AD the emperor Caracalla granted, with his well-known decree (constitutio Antoniniana), the Roman citizenship to all the free inhabitants of the Roman Empire. During the same period (in the 1st-2nd century AD), a remarkable presence of Thracians is testified by the inscriptions outside the borders (extra fines) both in the Greek territory and in all the Roman provinces, especially in the provinces of Eastern Roman Empire. Medieval history By the mid-5th century, as the Western Roman Empire began to crumble, Thracia fell from the authority of Rome and into the hands of Germanic tribal rulers. With the fall of the Western Roman Empire, Thracia turned into a battleground territory for the better part of the next 1,000 years. The surviving eastern portion of the Roman Empire in the Balkans, later known as the Byzantine Empire, retained control over Thrace until the 7th century when the northern half of the entire region was incorporated into the First Bulgarian Empire and the remainder was reorganized in the Thracian