In ancient geography, especially in Roman sources, Dacia was the land inhabited by the Dacians or Getae as they were known by the Greeks – the branch of the Thracians north of the Haemus range. Dacia was bounded approximately by the Danubius river, in Greek sources Istros (the Danube) or, at its greatest extent, by the Haemus Mons (the Balkan Mountains) to the south–Moesia (Dobrogea), a region south of the Danube, was a core area where the Getae lived and interacted with the Ancient Greeks–Pontus Euxinus (the Black Sea) and river Danastris, in Greek sources Tyras (the Dniester) to the east (but several Dacian settlements are recorded in part of area between Dniester and Hypanis river (the Bug), and Tisia (the Tisza) to the west (but at times included areas between Tisza and middle Danube). The Carpathian Mountains were located in the middle of Dacia. It thus corresponds to modern countries of Romania and Moldova, as well as smaller parts of Bulgaria, Serbia, Hungary, and Ukraine.
Dacians and Getae were North Thracian tribes. Dacian tribes had both peaceful and military encounters with other neighbouring tribes, such as Celts, Ancient Germanics, Sarmatians, and Scythians, but were most influenced by the Ancient Greeks and Romans. The latter eventually conquered, and linguistically and culturally assimilated the Dacians. A Dacian Kingdom of variable size existed between 82 BC until the Roman conquest in 106 AD. The capital of Dacia, Sarmizegetusa, located in modern Romania, was destroyed by the Romans, but its name was added to that of the new city (Ulpia Traiana Sarmizegetusa) built by the latter to serve as the capital of the Roman province of Dacia.