sentences:  He clearly benefited from his murderous plot against Eric.The "Historia regum" says that the province of Northumbria was henceforward administered by earls and records the formal appointment of Osulf as earl of Northumbria the following year.Likewise, the early 12th century "De primo Saxonum adventu" notes that "[f]irst of the earls after Erik, the last king whom the Northumbrians had, Osulf administered under King Eadred all the provinces of the Northumbrians."