Present-day Slovenia was inhabited by Illyrian and Celtic tribes until the Romans
conquered the region in the 1st century BC. Under Roman rule the territory was divided
three ways: part of it belonged to Venetia et Histria, the tenth region of Roman Italy
in the classification of Augustus, and the rest to the imperial provinces of Pannonia
and Noricum. The Romans established their main urban centres at Emona (Ljubljana),
Poetovio (Ptuj) and Celeia (Celje). Emona was an Italian town rather than a provincial
one, a point settled only in 2001 by a boundary stone found in the bed of the
Ljubljanica river.
The main route from the Pannonian plain into Italy ran through here, and the Romans
built military and trade roads to carry it. Mostly from the late 3rd century onward
they also fortified it. The Claustra Alpium Iuliarum, a chain of interconnected walls
and forts rather than a single rampart, closed the passes between Italy and Pannonia
around the Postojna Gate. Its centre was Castra ad Fluvium Frigidum at Ajdovščina, and
the hill fort of Ad Pirum on the Hrušica plateau was one of its principal fortresses.
In 394 the Battle of the Frigidus was fought in the Vipava valley below.
As the western empire weakened through the 5th and 6th centuries the area suffered
repeated invasions, and Alpine Slavs settled it in the late 6th century. Roman life
ended; Roman stone did not. It survives as town walls in a city park, as marble tombs
re-erected beside a village church, and as fort walls on a mountain pass. This page
lists what we have visited and documented so far, from the well known to the almost
forgotten.