), 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