The frontiers of the Roman empire together form the largest monument of one of the world's greatest states. They stretch for some 7,500km through 20 countries which encircle the Mediterranean Sea. The remains of these frontiers have been studied by visitors and later by archaeologists for several centuries. Many of the inscriptions and sculpture, weapons, pottery and artefacts created and used by the soldiers and civilians who lived on the frontier can be seen in museums. Equally evocative of the lost might of Rome are the physical remains of the frontiers themselves. The aim of this series of books is not only to inform the interested visitor about the history of the frontiers but to act as a guidebook as well. The province of Dacia had a relatively short life being abandoned due to economic and strategic reasons in the 260s. It was heavily militarized and therefore the role of the army was crucial in Its development and life. The Roman frontier In Dacia combined several elements, each relating to the landscape: there were riverain and mountain borders, some supplemented by linear barriers, and all connected by roads. Everywhere, the complex system of the border consisted primarily of a network of watchtowers, smaller or larger forts and artificial earthen ramparts or stone walls.

All the sources categories, epigraphy, literature and archaeology, together with the contributions of contemporary scientific methods form a solid foundation for the purpose of this paper: the study of the military hierarchy in Dacia. The most complex aspect is by far the hierarchy of soldiers. Epigraphic sources provide a rich source of data for Dacia but a less documented aspect is that of promotions and careers. Thus, the understanding of military hierarchy across the Empire is very valuable. Following the obvious hypothesis, that one cannot understand the history of Roman Dacia, unless in the wider context of the Roman Empire, the author attempts to decrypt the multitude of ranks and functions in the career of the solider. Thus, the research has moved from general to particular, starting from literary sources and contemporary monographic studies and reaching the individual epigraphic sources and studies concerned with a certain category of officers or a particular phenomenon found in an inscription. It was necessary to study each category of Roman units because the connections between them are very strong, especially as far as it involves soldiers, personnel and officers as elements of the whole functional entity in the Mediterranean space. For the purpose of systematization, the author chose the classification proposed by Domaszewski, more than 100 years ago, dividing the military ranks into several categories: soldier ranks - immunes and principales, centurions and primipili.