The monastery of Bangor of the Dee was known also as Bangor-is-Coed, i.e. "the eminent choir under the wood". The name Bangor was applied to several large monasteries, and is said to be derived from "Benedictus Chorus", shortened into Benchor, and subsequently written as Bangor.
The monastery on the Dee was distance about ten or twelve miles from Chester, and its ruins witness to its former extent and importance. St. Bede the Venerable (lib. II, c. ii.) says that it was filled with learned men at the coming of St. Augustine into England. Of the founder of this religious house and its history little if anything seems to be known, as all its chronicles, documents, etc. have been lost or destroyed.
We know, however, of its tragic extinction about the year 603. While the forces of Cadvan, King of North Wales, engaged those of the pagan and usurping Edilfrid of Northumbria, the monks were assembled on an eminence a short distance from the place of conflict. "The two armies", says Lingard, "met in the vicinity of Chester.
On the summit of a neighbouring hill, Edilfrid espied an unarmed crowd, the monks of Bangor, who, like Moses in the wilderness, had hoped by their prayers to determine the fate of battle. "If they pray", exclaimed the pagan, "they fight against us"; and he ordered a detachment of his army to put them to the sword...Chester was taken, and Bangor (monastery) demolished.
The scattered ruins demonstrated to subsequent generations the extent of that celebrated monastery" (Hist. Engl., II, 96). He adds in a note: "the number of monks slain on the hill is generally said to have been twelve hundred; but St. Bede observes that others besides the monks had assembled to pray. He supposes that the victory of Edilfrid fulfilled the predictions of Augustine."