At Easter time in that year, Sigfred dispatched envoys to Biesenstätt close to Worms in East Francia, who met with King Louis the German.
[1] Later in the same year, in August, Sigfred's brother Halfdan sent envoys to Louis in Metz in a similar issue.
They handed over a sword with golden handle as a gift from Halfdan, and asked Louis to accept the brothers as his "sons".
In an analogous fashion, Sigfred could be synonymous with, or a real life prototype for the Sigurd Snake-in-the-Eye of later sagas – also a son of Ragnar Lodbrok and a king in Denmark.
In the cataclysmic Battle of Leuven (891), two Danish vikings named Sigfred and Gudfred were reported to have been killed by the East Frankish king Arnulf of Carinthia.