838 - Horik demanded Friesland

Early Frankish shield
Frisia
A viking fleet was destroyed by a storm and an emissary from King Horik demanded that Louis the pious should give up Frisia and Wagria, but Louis the pious denied Horik`s demands, he was not that weak yet all though the Vikings had a victory in 837 near Walcheren.
England
The Anglo-Saxon Chronicle records that, a “great ship-horde came to Cornwall" and at the Battle of Hingston Down, Egbert of the West Saxons defeated the Danish and their West Welsh allies from Cornwall. It was the first time that Vikings had been recruited as mercenaries to help a Celtic people in Britain.

In 825, Egbert had established his kingdom as the strongest kingdom in Britain, he had crushed the Mercians at a place called Ellendun,outside Swindon. In 815, Egbert raided Cornwall “from east to west”. So the Cornish wanted revenge, but they were unsuccessful.