The Civitas Matthiacis (called often "Civitas or Aquae Mattiacorum", actual "Wiesbaden") was an administrative unit (civitas) in the right-bank part of the Roman province of Germania Superior (Upper Germany), whose governor resided in Mogontiacum, present-day Mainz.
The territory of the Civitas Mattiacorum extended between the rivers Moenus (Lower Main) and Rhenus (Rhine), which formed its likely southern border, and the Limes in the Taunus Mountains, which formed its northern border. The Kriftel stream (now the Schwarzbach) is considered the eastern border with the Civitas Taunensium, although Emil Ritterling also considers the Nidda River as an eastern boundary. The main town was Aquae Mattiacorum, present-day Wiesbaden. The name derives from the Germanic tribe of the Mattiaci, [1] presumably a sub-tribe of the Chatti, who were settled in the area around Wiesbaden, in the Taunus Mountains, and in the Wetterau region.
The Civitas Mattiacorum was an important civitas in the Roman province of Germania Superior during the first century. When Emperor Trajan moved the Roman garrison troops from the forts in Wiesbaden, Hofheim, Nida-Heddernheim, and Okarben to the Upper Germanic Limes in the Taunus and Wetterau regions around 110 AD, the occupied territories to the south, north of the Main River, were divided into two administrative districts: the Civitas Mattiacorum and the Civitas Taunensium (Vordertaunus and Wetterau).
Even after Rome withdrew to the left bank of the Rhine following the Germanic invasions of 259 and 260 AD, and the Alamanni conquered the area (the fall of the Limes), the district of Civitas Matthiacis likely remained as an administrative unit. It was devastated by Roman troops in 357 and 358 AD during Emperor Julian's punitive campaigns across the Rhine, and again in 371 AD during a similar campaign by Emperor Valentinian I.
The civilian settlement (called Vicus in Roman times) initially developed under the protection of the small forts in the area southeast of the main stone fort. The settlement boundary (inside actual Wiesbaden) ran roughly along Schwalbacher Straße to the Kochbrunnen spring, from there southeast to Mühlgasse, and to the south the vicus extended to just south of Maurergasse. No connection to the fort's main roads is apparent.
Like many civitas capitals that did not achieve the status of a Roman Colonia or Municipium, the settlement itself had the status of a Vicus, as evidenced by an inscription from 194 AD, which mentions the inhabitants as Vicani Aquenses. Another inscription mentions a praefectus aque(nsium) and also refers to the inhabitants' self-designation as Aquenses, which is also common in all other places with the name element Aquae [2] .
Besides its status as an administrative center, the thermal baths likely constituted a significant part of the city's economic foundation, about which little else is known. One inscription mentions a meeting house of merchants (schola der negotiatores civitatis Mattiacorum) and another a pottery merchant (negotiator artis cretariae).
The only known sanctuary in the city is a Mithraeum, discovered in 1902 near Coulin Street. The cult room was partially built into the eastern slope of the Schulberg hill. It featured side platforms for seating, a niche for the cult image, and a sacrificial pit in the center. The Mithraeum was built in the 3rd century and demolished around 360 AD for the construction of the "Heathen Wall" [3] .
