In mid-spring, a huge fleet of Saxons appears off the Caercolun coast. It sails to the Yar River and a horde goes ashore to sack Yarmouth. They re-embark and sail upriver only to disembark again near Norwich.
The Duke of Caercolun marches his army to battle, but the Saxons prove more numerous than expected, and his army is butchered. The Saxons assault Norwich, then starve out Buckenham and Thetford. They occupy those larger cities, and groups of Saxon warriors wander the countryside, robbing and killing. Thousands of refugees flee. When caught by Saxons, they are beaten and tied; they become thralls, or slaves, of the Saxons.
Cwichelm is the Saxon king. In fact, he and his people are not really Saxons at all, except in the generic sense. They are the Angles.