medieval sources used the Vlach exonym or its cognates, which all derived from the Common Slavic term for speakers of the Latin language. The earliest sources write of the Vlachs of the central territories of the Balkan Peninsula. Late Roman Age Scythia Minor and the limes on the Lower Danube (c. 270–c. 700) The territory between the Lower Danube and the Black Sea remained a fully integrated part of the Roman Empire, even after the abandonment of Trajan's Dacia. It was transformed into a separate province under the name of Scythia Minor around 293. Before 300, the Romans erected small forts at Dierna and in other places on the northern bank of the Danube in modern-day Banat. In their wider region, Roman coins from the periodmostly of bronzehave been found. The existence of Christian communities in Scythia Minor became evident under Emperor Diocletian (284–305). He and his co-emperors ordered the persecution of Christians throughout the empire, causing the death of many between 303 and 313. Under Emperor Constantine the Great (306–337), a bridge across the Danube was constructed at Sucidava, a new fort (Constantiana Daphne) was built, and ancient roads were repaired in Oltenia. The Lower Danube again became the empire's northern boundary in 369 at the latest, when Emperor Valens met Athanaricthe head of the Gothsin a boat in the middle of the river because the latter had taken an oath "never to set foot on Roman soil". The Huns destroyed Drobeta and Sucidava in the 440s, but the forts were restored under Emperor Justinian I (527–565). Eastern Roman coins from the first half of the 6th century suggest a significant military presence in Olteniaa region also characterized by the predominance of pottery with shapes of Roman tradition. Although Eastern Roman emperors made annual payments to the neighboring peoples in an attempt to keep the peace in the Balkans, the Avars regularly invaded Scythia Minor from the 580s. The Romans abandoned Sucidava in 596 or 597, but Tomis, which was the last town in Scythia Minor to resist the invaders, only fell in 704. North of the limes (c. 270–c. 330) Transylvania and northern Banat, which had belonged to Dacia province, had no direct contact with the Roman Empire from the 270s. There is no evidence that they were invaded in the following decades. Towns, including Apulum and Ulpia Traiana Sarmizegetusa, and the surrounding areas continued to be inhabited