Norse sagas recorded a battle at Hringmaraheior; Old English Hringmere-hūō, modern name Ringmere Heath.[1]
The sack of Thetford occurred in 1004. Sigvat records the victory of King Ethelred, allied with Saint Olaf,[2] over the Danes under Sweyn Forkbeard during the latters campaigns in England.
The Battle site was located in lands under the control of Ulfketel, Thane of East Anglia, at a site once thought to be near Wretham[2], but now thought to be at Rymer in Suffolk (Keith Briggs, The battle-site and place-name Ringmere, Notes and Queries Volume 58, Issue 4 p.491-492 (2011)], | link to text). The Anglo-Saxon Chronicle reports that Ulfketel/Ulfcytel and the "councillors in East Anglia" attempted to buy a truce with Swein, but that the Danes broke the truce and marched to Thetford where a part of the East Anglian fyrd engaged them. The Danes managed to escape.
The Battle of Ringmere was fought in 1010; John of Worcester records that the Danes defeated the Saxons. Over a three month period the Danes wasted East Anglia, burning Thetford and Cambridge.[1]