High Quality Content by WIKIPEDIA articles! Roman Dacia, also Dacia Traiana or Dacia Felix , was a province of the Roman Empire (106-271/275 AD). Its territory consisted of eastern and southeastern Transylvania, the Banat, and Oltenia (regions of modern Romania). Dacia was from the very beginning organized as an imperial province and remained so throughout the Roman occupation. Historians estimates of the population of Roman Dacia range from 650,000 to 1,200,000. The conquest of Dacian kingdom was achieved by Emperor Trajan in the Dacian Wars (101-102 AD, 105-106 AD) against Decebalus. The Trajan's Column in Rome describes the wars in bas relief. But the territory of the Dacian kingdom was not occupied in its entirety by the Roman Empire; the greater parts of Moldavia, Maramure and Cri ana, remained controlled by Free Dacians after the Roman conquest.