Original: Accession His cognomen, "The Peaceable", was not necessarily a comment on the deeds of his life, for he was a strong leader, shown by his seizure of the Northumbrian and Mercian kingdoms from his older brother, Eadwig, in 958.
Simplified: He won the nickname, "the Peaceable", but in fact was a stronger king than his elder brother, Edwy, from whom he took the kingdoms of Northumbria and Mercia in 958.