Æthelred (/ˈæθəlrɛd/; c. 762 – 18 April 796), was the king of Northumbria from 774 to 779 and again from 790 until he was murdered in 796. He was the son of Æthelwald Moll and Æthelthryth and possibly became king while still a child after Alhred was deposed.
The origin of Æthelred's family isn't recorded, but his father Æthelwald, who was also called Moll, seems to have come from a noble background. Æthelwald first appears in the historical records in a letter written by Pope Paul I to king Eadberht, ordering him to return lands taken from an Abbot Fothred, which were given to his brother Moll. After the abdication of king Eadberht in 758, his son Oswulf took his place but despite his father's long reign and his powerful uncle Ecgbert, he was murdered just a year later in 759 at Market Weighton by his own bodyguards. The murder was possibly ordered by Æthelwald as he became king soon after. In 761 Oswulf's brother Oswine met Æthelwald in battle but Oswine was killed in the fighting at Eildon Hill on 6 August.
After his victory, Æthelwald married Æthelthryth at Catterick on 1 November 762. Æthelwald was deposed as king on 30 October 765, by a council of noblemen and prelates, and replaced by Alhred, the brother-in-law of Oswulf and Oswine.
After ruling for nearly ten years, the Northumbrians drove out King Alhred from York in 774. They then chose Æthelred as their king and he was "crowned with such great honour". In the year after his accession Æthelred, who may have been influenced by his father Æthelwald, ordered the killing of an Ealdorman, Eadwulf..