In 926, Aethelstan visited Ripon as part of measures to establish he kingdom's boundaries. Soon after, the Vikings led by Eric Bloodaxe took over the areas around York, and in 948, Eadred moved north to remove this invaders destroying Ripon Cathedral in the process. Little is known of the history of the Cathedral until around 1180 when Archbishop Roger initiated a Norman church on the site. Building work continued and was modified and completed in around 1260 by Archbishop Walter de Grey. Archbishop Roger is linked to the death of Thomas Becket as Roger sided with Henry against Becket and was regarded as accessory to the murder.