Leslie Stephen,
Dictionary of National Biography…
(1898)
“ He left thirty ships in England, however, and urged Cnut to return thither. In the campaign which followed Cnut's return to England he was prominent, leading the Danish forces at Sherstone in Wiltshire (Geoffrey Gaimar, Lestorie des Engles, ap. Petrie, Mon. Hist. Brit. i. 816) , and being present with Cnut at the battle of Assandun in Essex (Encomium, ii. 8) . Cnut acknowledged his great debt to Thurkill when in 1017 he divided England into four earldoms by giving him that of East-Anglia (A.-S. Chron. ii. 124) . ”
