On the Dating of the Norse Siege of Chester

There is only one account of the Norse siege of Chester, found in Fragmentary Annals of Ireland (FAI). FAI does not provide a date for the siege (it rarely provides dates at all) but does place it within the reign of Æthelflæd in Mercia (c. 886–918), and prior to the death of her husband Æthelred. The latter sets a terminus ante quem of 911. Otherwise, the annal for the siege gives few other clear indicators of date. Nonetheless, it is widely accepted that the siege of Chester occurred in 907. This dating, however, rests on shaky foundations. It needs to be revised in reference to FAI’s internal dating schema, derived from the correlation of its entries with those of external sources, and to the political landscape of early tenth-century Mercia. These suggest the year 910 as a more likely date.