Constantia
Constantia (Coutances), a place in the NW. of Gallia, which Ammianus (15.11) calls Castra Constantia. In the Notitia the Civitas Constantia is mentioned as being in Lugdunensis Secunda. A local tradition assigns the foundation of this place to Constantius Chlorus, the father of Constantine. Ammianus says that the Sequana (Seine) enters the sea near Constantia; but his geography of Gallia is very inexact. The name of the Pagus Constantinus is the origin of the name Côtantin, which in the ante-revolutionary geography of France designated the peninsula in which Coutances is situated.
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.