In 1004 Ulfcytel Snillingr was appointed Earldorman East Anglia.
Anglo-Saxon Chronicle. 1010. This year came the aforesaid army, after Easter, into East Anglia; and went up at Ipswich [Map], marching continually till they came where they understood Ulfcytel was with his army. This was on the day called the first of the Ascension of our Lord. The East-Angles soon fled. Cambridgeshire stood firm against them. There was slain Athelstan, the king's relative, and Oswy, and his son, and Wulfric, son of Leofwin, and Edwy, brother of Efy, and many other good thanes, and a multitude of the people. Thurkytel Myrehead first began the flight; and the Danes remained masters of the field of slaughter. There were they horsed; and afterwards took possession of East-Anglia, where they plundered and burned three months; and then proceeded further into the wild fens, slaying both men and cattle, and burning throughout the fens. Thetford [Map] also they burned, and Cambridge [Map]; and afterwards went back southward into the Thames; and the horsemen rode towards the ships. Then went they west-ward into Oxfordshire, and thence to Buckinghamshire, and so along the Ouse till they came to Bedford [Map], and so forth to Temsford, always burning as they went. Then returned they to their ships with their spoil, which they apportioned to the ships. When the king's army should have gone out to meet them as they went up, then went they home; and when they were in the east, then was the army detained in the west; and when they were in the south, then was the army in the north. Then all the privy council were summoned before the [his future father-in-law] king (age 44), to consult how they might defend this country. But, whatever was advised, it stood not a month; and at length there was not a chief that would collect an army, but each fled as he could: no shire, moreover, would stand by another. Before the feast-day of St. Andrew came the enemy to Northampton [Map], and soon burned the town, and took as much spoil thereabout as they would; and then returned over the Thames into Wessex, and so by Cannings-marsh, burning all the way. When they had gone as far as they would, then came they by midwinter to their ships.
In 1016 Ulfcytel Snillingr died.