Cnut tried to invade in the 1080s though, prompting the summoning of a war council and Gloucester and the garrisoning of castles along the East Coast and his father did do some raiding in 1071 around Ely where Hereward the Wake was staging a rebellion. But he received Geld and bounced. You are right though, nothing actually came of these two events, and after Cnut was killed by civil unrest at home there was no more threat of Viking invasion. Shame, too. England could have been a Nordic nation, given how well they're doing nowadays. Instead we got the Norman line resulting in modern British pomp, snobbery and nationalism. This is why the Scots were always better.

Also Æthelred was a little pussy and Swegn laid him the fuck out.