The antiquary Leland mentions two Roman inscriptions as built into the city wall near Southernhay, but they are gone, and besides the inscribed dagger we have only a seal of Severius Pompeyus, and sundry graffiti or funereal pottery, in the way of literary relics of Roman Exeter. The poverty of Devonshire in memorials of the Roman period is shown by the fact that, outside Exeter, there are not a dozen places in the county which have yielded Roman vestigia other than coins. In 926 the Britons were driven from Exeter by Athelstan, who banished them into Cornwall, and fixed the River Tamar as their boundary. Athelstan was one of the greatest benefactors the city has had; for, in addition to increasing the fortifications by means of a massive wall flanked by towers, he built a castle on the Red Mount, now known as Rougemont Castle. Although very little of this now remains, a portion of the ruins is generally known as "Athelstan's Tower", and has a window with a triangular head, which is certainly of Saxon style and date. In 932 Athelstan rebuilt the Monastery of Our Lady and St. Peter, staffing it with monks of the Benedictine Order, and presenting them with the reputed relics of St. Sidwell, a saint who is still somewhat of a puzzle to ecclesiologists. A few years later the monastery was plundered by the Danes, when the monks beat a hasty retreat, but returned in 968 on the entreaty of King Edgar. A mint was shortly established here, wherein the first coins were struck naming Athelstan "King of England". The Danes made continuous raids in the neighbourhood, but were decisively defeated by the West Countrymen in 1001, at Pinhoe, a few miles from Exeter. From that time until the treacherous massacre of the Danes in Wessex upon St. Brice's Day in 1002 by Ethelred, this part of the country was comparatively free from their inroads; but Gunhilda, the sister of Swegen, King of Denmark, being among the slain, this king came to avenge her death. He sailed up the Exe, burning and plundering the villages on its banks, and for four years his army marched in every direction across Wessex, and was at length induced to withdraw on being paid a _wergeld_ (war tax) which was first levied on Exeter.