Frontiers of the Roman Empire – Dacia, Romania

The Roman Empire was among the greatest in the world in terms of size and longevity. At its height, it encircled the Mediterranean. By the end of the 2^nd century CE, its borders extended for around 7,500 kilometres across Europe, North Africa and the Middle East.

The Dacian segment of the frontier was established after Emperor Trajan’s conquest of the Dacian kingdom in the early 2^nd century CE and, with a length of more than 1,000 kilometres, it was one of the largest and most complex Roman frontier segments in Europe.

A series of impressive high-altitude marching camps provide evidence of the determined journey of Trajan’s armies towards the Dacian strongholds. These temporary camps were set up by the army for stopovers, at a distance of around a day’s march away from each other.

Of the different types of military base, the largest and most monumental were legionary fortresses, three of which were built in Dacia, along the province’s main road. A telling testament to Rome’s power, they accommodated between 5,000 and 6,000 elite heavy infantry soldiers.

Similar to legionary fortresses but smaller, auxiliary forts were built in much higher numbers. They served as bases for auxiliary regiments of 500 to 1,000 infantry and/or cavalry soldiers. In some cases, several military units were quartered in the same fort.

These structures, which complete the complex military system of Dacia, were used to oversee, direct or block movement across the border, and include over 180 watchtowers, as well as significant segments of ramparts and stone walls, which are today found mostly in forested areas. 

Over time, civilian settlements developed around most military bases. These settlements were inhabited by the people who were directly associated with the army, such as soldiers’ families, veterans, merchants and artisans. Their population could be very culturally diverse.

Some of the civilian settlements became true urban centres, which particularly flourished at the beginning of the 3^rd century CE, when Dacia was rewarded for its support of the Severan dynasty with unprecedented investments in infrastructure, architecture and urbanism. 

The Dacian Limes was modelled in accordance with the varied landscape, the nature of the access and communication routes and the perceived level of threat at each point, and can be divided into several sectors:

The south-western sector of the limes began at the Danube. It consisted of two parallel branches of imperial road (the Roman equivalent of today’s highways), the westernmost of which was short-lived. They led to Dacia’s first city, Colonia Ulpia Traiana Dacica Sarmizegetusa.

The western limes is also defined by the imperial road, which was guarded by legionary fortresses and large auxiliary bases. Fortlets which were connected by smaller military roads oversaw the highly important task of defending the gold-bearing Apuseni Mountains.

In the eastern sector, a good degree of natural protection was provided by the Eastern Carpathian Mountains. Sparsely arranged auxiliary forts focused on the sector’s most important mountain passes, while communicating with the more advanced watchtowers.

In the south-east, the first of two defensive lines across the Wallachian Plain was a riverine frontier. This sector, the limes Alutanus, was defined by the course of the Olt River as it flows into the Danube. Most of the auxiliary forts of this sector are smaller than average. 

The frontier protected Dacia from ‘barbarian’ incursions, enabling the development of Roman culture and civilization, for almost 170 years. It fell into disuse in 271 CE, when Emperor Aurelian withdrew the Roman army from the area during the general crisis of the Empire.

The 277 component parts that make up this World Heritage property have retained a high degree of authenticity, therefore allowing great insight into not only the workings of the Dacian limes, but also the complexity of the frontiers of the Roman Empire at a European level.