On the site of the current fortress, during the last two millennia, several strong fortifications succeeded one another from the ancient Roman fortress to the modern, Vauban-type one. The Roman fort lasted more than one millennium. Its walls were repaired and reinforced repeatedly.
Its beginnings are connected with the conquest of the Dacian kingdom by Emperor Trajan at the end of two major wars between the Romans and the Dacians (101-102 and 105-106 AD). The legionary fortress was built in two stages, from 106 to 132 AD. Initially, it was built only of wood and earth, and had only simple constructions within its walls. Strong stone walls were erected after the death of Trajan, during the reign of the next emperor, Hadrian (117-138 A.D.). The walls of the fortress, with a thickness of 3 meters, were built with massive blocks of chalk using the technique known as opus quadratum. The foundations of the walls consist of quarry stone and boulders. The fortress was rectangular in shape with sides measuring ca. 440x400 meters. It had four gates.
Adalbert Cserni began the first archaeological investigations within the Roman Fortress of Apulum. He undertook archaeological excavations from 1888 to 1916, with some interruptions. In the course of his research, he discovered the bases of some barracks (soldiers’ dwellings) and the traces of Roman walls on the southern and south-western sides of the fortress, as well as amassing an important collection of archaeological and epigraphic materials.
It took more than half a century before the hypothesis regarding the Roman origin of the walls of the medieval fortress was advanced. This hypothesis was based on plans of the fortress as drawn on maps from 1687 (Pianta d’Alba Iulia) and 1711 (Giovanni Morando Visconti), both preceding the construction of the Vauban-type fortress. This opened up a new and unexpected perspective on the recovery of a piece of history that was considered lost.
The main archaeological excavations of the Roman fortress, which began soon after these hypotheses were aired, confirmed the suppositions of specialists. The investigations focused on the defensive elements of the fortress, especially on the access gate (porta principalis dextra) on the southern side, which had a central pillar and rectangular flanking towers. The double entrance was preserved in situ, and is presently open for tourist access. On the southern side, the Roman wall was well preserved for a length of 150 meters and height reaching five meters, as well as important segments, such as that of the Palace of Princes, where the ancient walls had been incorporated into medieval buildings.
Little is known about the other three gates and sides of the fortress. It is worth remembering that in the Middle Ages, people preserved two of the ancient access ways, namely the western gate, called St. Michael, and the eastern one, called St. George, which functioned until the old fortress was replaced by the Vauban-type one. The Roman origin of the towers of the medieval gates seems to be supported by reports by seventeenth century travelers, which mention the presence of a relief sculpture placed above the eastern gate (St. George) representing the she-wolf suckling Romulus and Remus, the legendary founders of Rome.
During the recent restoration undertaken in the fortress, extensive surfaces within the Roman fortress were excavated. Untouched upon areas were excavated. These offered numerous indications of the evolution and dynamic of military activities inside the fortress. Not surprisingly, abundant traces of buildings used by legionaries, such as administrative spaces, barracks, and street portions, came to light. The buildings belonging to the Principia complex were conserved in a museum, which was especially designed to protect the Roman ruins.
Even though it was not the largest fortress of Roman Dacia, Apulum Fortress’ exceptional strategic importance and the role of the military unit stationed here—Thirteenth Gemina Legion—make it the only fortification of this kind that was used throughout the existence of the province. Its fate was intimately connected to that of Dacia. The loss and subsequent withdrawal of the Romans from the province did not mean that this grand military architectural monument disappeared. On the contrary, medieval people discovered the strong white chalk walls and renamed the place Bălgrad (White Fortress), later Fehérvár or Weissenburg. The ancient walls served the needs of the people at the turn of the first millennium, and later those of the bishops and later still those of the princes of Transylvania. Today, thousands of tourists visit the site of Ancient Apulum. (C.I.P)