Archbishop of York Wulfstan supported Eric, but the current Anglo-Saxon king, Eadred, came north in 948 and destroyed part of Northumbria as punishment, even burning several buildings at Ripon (a significant place, it was founded by St. Wilfrid and housed the remains of St. Cuthbert at one time). The he departed the north, he advised that he would return with greater devastation if they did not get rid of Eric.
That did not resolve the "northern trouble," however, because shortly after, King Malcolm I of Scotland raided Northumbria and took captives and stole cattle. Moreover, with Eric gone and Eadred back south, Amlaib returned in 949, so one record claims. That only lasted until 952 when, once again, the Northumbrians expelled him, whereupon Eric returned to reign from 952 - 954.
Eric might have stayed longer except for a betrayal. A history written a century later by Roger of Wendover says he was:
King Eric was treacherously killed by Earl [consul] Maccus in a certain lonely place which is called Stainmore, with his son Haeric and his brother Ragnald, betrayed by Earl [comes] Oswulf; and then afterwards King Eadred ruled in these districts.
After this, Oswulf administered Northumbria and was loyal to Eadred and the following English kings. Northern control by Vikings was a thing of the past. The identity of maces is unknown. It is assumed that Roger of Wendover had access to a txt with details of the death that is no longer available to modern scholars.
Tradition tells that Oswulf ruled all of Northumbria for about the next decade, so I think he's worth talking about. See you tomorrow.