The Saalburg is a former Roman Cohort Fort located northwest of Bad Homburg in Hesse and belonging to the Limes Germanicus. This fort served for 150 years as a base for frontier troops. The Saalburg is the most completely reconstructed Roman fort in Germany and serves as a research institute and open-air museum. It is part of UNESCO‘s “Upper-German Raetian Limes“ World Heritage Site.
Towards the end of the 1st century AD, the Romans occupied the area of the Taunus and erected a simple wood-and-earth fort at the Saalburg Pass to house a numerus (units of barbarian allies) and control traffic on this important route. It had a rectangular ground plan, corner towers, intermediate towers and two gates and was surrounded by a ditch.
Around 135 AD, the old timber fort was converted into a larger cohort fort measuring about 147 x 221 m and consisting of walls built from a solid combination of stone and timber beams. The cohort fort was occupied by the Cohors II Raetorum civium Romanorum equitata, an auxiliary unit made of about 480 foot soldiers and 120 cavalrymen. The troops were tasked with monitoring the Limes which can still be seen today north of the Saalburg. In the fort’s interior, wooden barracks were built to accommodate the troops, their animals and supplies. A civilian settlement (vicus) developped along the road leading to Nida (today, Frankfurt-Heddernheim).
In the middle of the 2rd century, the cohort fort was extended and rebuilt in stone. An earthen ramp reinforced the inner side of the defensive walls and the four gates took their final shape. Inside the fort, the original half-timbered buildings were partly replaced by massive stone structures. Around 200 AD, the village reached its greatest extent. As many as 2000 people may once have lived in the fort and the vicus.
In the early 3rd century, the situation along the limes became increasingly unsettled. The fort and the vicus fell into disrepair after an attack by Germanic tribes. Campaigns in the East of the Empire and the Germanic threat to the Roman frontier after 260 AD forced Rome to abandon the limes and with it the Saalburg. After the abandonment of the Upper Germanic Limes, the fort was used as a quarry.
The first archaeological excavations at the Saalburg began in the middle of the 19th century. In 1897, Kaiser Wilhelm II initiated the reconstruction of the ancient Roman fort. Between 1897 and 1907, the fort was rebuilt on its stone foundations; the stone defense wall with the earth embankment behind it and the four gates, the principia, the horrea, parts of the conjectured praetorium, two troop barracks were erected. However, with the insights gained by the field of archaeology over the past 120 years, a different conception of some aspects of Roman military architecture has developed. The buildings erected since 2004 (the praetorium, the fabrica) reflect the modern understanding of the fort.
The Saalburg also houses the Saalburg Museum, one of the two most important institutions dedicated to the study of the German Limes (the other being the Limesmuseum of Aalen). Today, the remains of the 550 kilometre-long frontier complex stretching from the Rhine down to the Danube comprise the largest ancient monument in Europe.