Question: Who was the most famous king of the House of Griffins, and King of Sweden, Denmark and Norway in the 14th and 15th centuries?
Sentence (from "House of Griffins"): The House of Griffins or House of Pomerania (German: "Greifen" ; Polish: "Gryfici" ), also known as "House of Greifen", was a dynasty of dukes ruling the Duchy of Pomerania from the 12th century until 1637.
Relevant evidence: No