The first records of human settlement in this area are in the form of the material remains of the ancient settlement Servitium near Stara Gradiška. Although, according to Tabula Peutingerian, this settlement was located on the right bank, the remains of this ancient locality were found in the centre of the forest triangle, Prašnik. This can be explained by the former meandering of the River Sava. The ancient settlement was situated on the road leading from Siscia (Sisak) eastward and it had the role of a minor post and relay station (mutationes) used for changing horses or teams. (1)
Thorough research has not yet been carried out, and a thin layer of forest soil hides numerous hillocks containing fragments of tiles, bricks, gutters and flagstones.
The route of the former Roman road leading from the settlement northward, was used for the construction of the forest railroad and after the Second World War it was used for forest exploitation in that part of Slavonia. (2) In an administrative sense, this area was part of Panonia Superior.
The location of the ancient settlement near the River Sava facilitated transport by river, but at the same time, due to the high water level, it rendered road travel more difficult and uncertain. The hydrologic condition of the River Sava at the time of the Roman Empire is not known, but we know that there were possibilities to modify the river's course and provide access to the river (construction of dams, reclaiming marshland and construction of a port and pier).
The position of Servitium established links with the west (Siscia) and the east (Sirmium - today Sremska Mitrovica), and through the nearby settlement, Urbate (today Davor), across the valley of the River Vrbas with the province of Dalmatia.
There is evidence of rich historical heritage in the preserved remains of ancient buildings in Benkovac and Cage. They are situated approximately fifteen kilometres north of Stara Gradiška on the banks of a brook, previously known as Lješnica but later renamed Sloboština for no apparent reason.
Road links with Servitium had to be established for administrative and military reasons. The route of the modern road Stara Gradiška - Okučani Bijela Stijena lies on the foundations of the ancient and medieval roads.
The archaeological site, "Otrnci", in Benkovac is known for the largest preserved tloor mosaic which was part of the ornamental architecture of a prestigious Roman villa. The mosaic covers the whole surface of the central 10 x 9 m room, and it is made of tiny white and greyish-blue stone cubes and red bricks. The central square medallion contains four geometrical ornaments in the angles and a circular three-strand interlaced decoration fil.led with blue and red triangles." (3)
Some foundations were found dating from the late Roman period in the neighbouring village Cage at the end of the nineteenth century. In the archaeological magazine ("Arheološki vjesnik") of 1898 the historian, Josip Brunšmit, describes two stone reliefs that made up part of a Roman sarcophagus ornament. These unintentional finds were later confirmed by the discovery of a larger building in "Staro selo" in Cage.
At the beginning of the last century, further remains of large buildinas dating from Roman times were found on Vlaislav hill near Bodegraja. Bricks with the inscription LEG II and LEG VII, Roman coins and a stone statue representing a Roman house god with the inscription EQUEAS were also found and sent to the Archaeological Museum in Vienna. (4)
Although Servitium was plundered and destroyed by invading Barbarian tribes at the end of the fourth century, along with all other settlements under Roman rule in the area of Panonia Superior, its excellent strategic and road communication position ensured that life continued on the ruins of what was an ancient settlement. Other tribes and nations who gradually appeared on the historical stage, started developing a new life close to these ruins. The area continued to demonstrate the reasons why it was chosen in ancient times, its natural advantages which have remained unchanged to the present day. Being a strategic point it was, however, often threatened and attacked as an important starting point by invaders who usually came from the east both in the past and in recent years.
The early middle ages are not well documented but the area surrounding Gradiška on the River Sava shared the fate of the rest of Slavonia.
Croatian tribes established their settlements on the ruins of Roman villages but they were not able to integrate the achievements of ancient civil engineering into their own technological and engineering experience. Even if early Slavic architecture had existed in this area, it would not have been preserved since timber was the basic construction material. The technique of building was acquired only several centuries later and the oldest preserved fortifications date from that time. These remains are partially preserved or there is written widence of their existence in historical sources.