Mons Brisiacus
Mons Brisiacus This is one of the positions in the Roman Itins. along the Rhine. They place it between Helvetum or Helcebus [HKLCEBUS] and Urunci. There is no doubt that is Vieux-Brisach or Altbreisach, as the Germans call it. All the positions of the Itins. on the Rhine are on the west or Gallic side of the river, but Vieux-Brisach is on the east side. The Rhine has changed its bed in several parts, and this is one of the places where there has been a change. Breisach is described by Luitprand of Pavia (quoted by D'Anville), as being in the tenth century surrounded by the Rhine in modum insulae.
It may have been on an island in the Roman period. The hill (mons) of Altbreisach is a well marked position, and was once crowned by a citadel. Altbreisach is now in the duchy of Baden, and opposite to Neubreisach on the French side of the Rhine.
From William Smith (ed.), Dictionary of Greek and Roman Geography. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.