sentences:  From Irish annals it is known that Edmund's old rival Olaf Guthfrithson left Dublin in 939 ("Annals of the Four Masters"), that in 940 his cousin, known in Ireland as Amlaíb Cuarán and in England as Olaf Sihtricsson, joined him in York ("Annals of the Four Masters", "Annals of Clonmacnoise") and that Olaf Guthfrithson died in 941 ("Annals of Clonmacnoise"," Chronicon Scotorum"), while the "Anglo-Saxon Chronicle" (MS E) dates his death – incorrectly it seems – to 942.Amlaíb Cuarán succeeded him and did so with popular support, as the "Anglo-Saxon Chronicle" (MS D) reports that in 941, "the Northumbrians belied their pledges, and chose Olaf [i.e.Amlaíb Cuarán] from Ireland as their king."