“The name occurs in the form hremmes byrig in a Saxon charter of A.D. 940 (Chron. Monast. Abingdon, vol. 1, p.70), and means ‘raven’s fort’.”
The Scouring of the White Horse
G. W. B. Huntingford
The Journal of the Royal Anthropological Institute of Great Britain and Ireland, Vol. 87, No. 1. (Jan. – Jun., 1957), p. 105.
With the site name meaning 'Ravens Fort' in A-S, could this be a Alfred vs the Danes naming? i.e. related to the battle of Ashdown. The Danes would have had a Raven Banner for Odin. Raven's are usually associated with battle (being creatures of carrion).