Page "Narbonne" Paragraph 10

The changes to the long seashore which resulted from the silting up of the series of graus or openings which were interspersed between the islands which made up the shoreline ( St. Martin ; St. Lucie ) had a more serious impact than the change in course of the river.

Other causes of decline were the plague and the raid of Edward, the Black Prince, which caused much devastation.

The growth of other ports was also a factor.