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 .