Norse sagas recorded a battle at Hringmaraheior; Old English Hringmere-hūō, modern name Ringmere Heath. The sack of Thetford occurred in 1004. Sigvat records the victory of King Ethelred, allied with Saint Olaf, over the Danes under Sweyn Forkbeard during the latters campaigns in England. 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.