Question: Danish Viking, who ruled over parts of Friesland between 841 and 873 was the uncle of a Viking leader who raided the British Isles, West Francia, Frisia, and Lotharingia in the 860s and 870?
Sentence (from "West Francia"): West Francia was formed out of the division of the Carolingian Empire in 843 under the Treaty of Verdun after the death of Emperor Louis the Pious and the east–west division which "gradually hardened into the establishment of separate kingdoms (...) of what we can begin to call Germany and France."
Relevant evidence: No