Pont-de-l’Arche or Pitres? A location and archaeomagnetic dating for Charles the Bald’s fortifications on the Seine
By Brian Dearden and Anthony Clark
Antiquity, Vol. 64 (1990)
Introduction: Charles the Bald (grandson of Charlemagne) ruled the West Franks from AD 843 to 877. During these years his kingdom took the brunt of the Danish Viking attacks, mainly concentrated on the Seine and Loire rivers, with Paris and Orleans as principal targets. Despite military successes by the Franks, the raids continued until the tactic was evolved of blocking the rivers by the use of fortifications. In 862 the defence of the Seine was undertaken over a number of years at a site near to Pitres. In 866 the Vikings left the Seine. The Loire was blocked a few years later by fortifications at Ponts-de-Ck, near Angers.
Documentary evidence for these river defences begins with the statement made in 862: Charles. . . made all the leaders of his kingdom meet at a place which is called Pistis [Pitres]. where on the one side the Andelle and 0n the other side the Eure flow together into the Seine. They came about the beginning of June with many workers and carts, constructing fortifications on the Seine blocking off the entry of ships going up or down the river on account of the Northmen.