Input (grade 13): Godwinson was subsequently defeated within a month by another Viking descendant, William, Duke of Normandy (Normandy had been acquired by Vikings (Normans) in 911).
Output (grade 9): Harold Godwinson was subsequently defeated within a month by William, Duke of Normandy, who was another descendant of Vikings. Normandy had been acquired by Normans (Norsemen) in 911.