790. Osred of Northumbria exiled (flees to Isle of Man)
Æthelred, Æthelwold Moll's son, again succeeds to Northumbria
The Chronicle notes only that Osred was betrayed and driven out of the kingdom and that Æthelred succeeded. Simeon of Durham adds that Osred was deceived by his nobles, taken prisoner and deprived of the kingdom, tonsured at York, and forced into exile. (That from his Historia Regum; in his History of the Church of Durham he adds that Osred fled to the Isle of Man.) The nobles are not named, but it would be interesting to know whether Sicga was still among them (we know nothing of him between his killing of Ælfwold in 788 and his own death in 793).
The first couple of years of Æthelred's second reign (his first reign was 774-778/9) show him moving quickly to eliminate opposition, killing the sons of King Ælfwold in 791 (Ælfwold himself had been killed in 788), and killing King Osred on his return in 792. His attempt to kill Ealdorman Eardwulf was unsuccessful, and it might have been seen as poetic justice that it was this same Eardwulf who eventually succeeded him in 796. His marriage to a daughter of Offa of Mercia in 792 gained him a strong southern ally, who incidentally favoured the same approach to getting rid of superfluous rivals, as his beheading of Æthelberht of East Anglia in 794 makes clear. Almost nothing is known of Æthelred's domestic affairs after 792: it is the Viking onslaughts of 793 and 794 which attract the attention of the chroniclers.
That at least one contemporary observer thought things were pretty dire in the state of Northumbria can be seen from a letter Alcuin wrote to Æthelred and his nobles after the sack of Lindisfarne (EHD 193), suggesting that the Vikings might be divine punishment for the manifold sins of the English. Alcuin is politic enough not to limit his criticism to Æthelred's reign, saying things had been bad since King Ælfwold's day (778/9-788). Since his visit in 786 for the council with Ælfwold and the papal legate was the last occasion before this letter that we know Alcuin was in Northumbria, it would be unwise to use the letter as an indication that things were worse in Æthelred's reign. It is also clear that Alcuin was well aware of scriptural explanations of foreign invasions allowed as divine vengeance for the sins of a chosen people: in following this model he stands four-square in a literary tradition that in Britain goes back to Gildas in the 6th century and forward to King Alfred in the 9th and Wulfstan in the 11th. This is not necessarily to deny the truth of Alcuin's observations, but to point out that he was collecting facts to back a particular thesis, and like Wulfstan's long catalogue of the sins of the English in the reign of another King Æthelred troubled by Viking invasions (see entry on 978), he was looking with a dark-adapted eye.