Question: Óttarr svarti ("Óttarr the Black") was an 11th-century Icelandic skald, he was the last court poet, finally of which King of Denmark, England and Norway; together often referred to as the North Sea Empire?
Sentence (from "Óttarr svarti"): His poems are significant contemporary evidence for the careers of Óláfr Haraldsson and Cnut the Great.
Relevant evidence: No