820-834 - Ferocious attacks from the Viking forces against Western Scotland, force King Angus II to move his court east from Argyll.

836 - Rise of Prince Kenneth mac Alpin with the help of his Norse allies from the Hebrides.

834 - Death of King Angus II of the Scots & Picts. He is succeeded by his nephew, Drust mac Constantine.

837 - Death of joint-Kings Drust and Talorgen of the Scots & Picts. They are succeeded by their cousin, Eoganan mac Angus.

839 - The Norsemen massacre the united Dalriadan and Pictish house of Fergus. Death of King Eoganan of the Scots & Picts and also of his brother, Bran. Prince Kenneth mac Alpin uses his influence to install his father, Alpin mac Eochaid as King of Dalriada. Ferach mac Bargoch, probably a maternal cousin of the late King, manages to secure the Pictish throne through the right of his mother.

841 - Death of King Alpin of Dalriada. He is succeeded by his son, Kenneth.

c.846 - King Drust mac Ferach receives military assistance from King Aethelred II of Northumbria in his fight against the expansive Scots.