[2] The fort may be of Iron Age origin, but was rebuilt and fortified as a burh by King Alfred, as part of his defense against Viking raids from the Bristol Channel around 878 AD.

It would have been one of a chain of forts and coastal lookout posts, connected by the Herepath, or military road, which allowed Alfred to move his army along the coast, covering Viking movements at sea.

Excavations have revealed a first phase of defence with a mortared wall fronting an earth bank from this period.

In the Burghal Hidage of 919, nearby Watchet is attributed 513 hides, which converts to a defensive perimeter of 645 m. It is not clear whether this refers to the walls of the town, or of Daw's Castle high on the cliff above.

The Anglo-Saxon Chronicle records a Viking raid on Watchet in 914, but they were defeated with great slaughter ... so that few of them came away, except those only who swam out to the ships.