If the Norman Conqueror himself gained no direct advantage from the castle which he required D'Oilgi to build, his policy certainly bore its fruit in the days of his grandchildren. In the civil wars of Stephen's reign Brien Fitzcount was a leading supporter of Maud, the daughter of Henry Beauclerk and widow of the Emperor Henry IV. of Germany. The escape of the Empress from Oxford Castle, her flight in white garments through snow and ice by night to Abingdon, and her safe arrival at Wallingford Castle, are a familiar tale, perhaps embellished through the ages, but well grounded in history. Stephen set up opposing forts across the river at Crowmarsh, and traces of them may still be seen on either side of the road near the eastern end of the bridge, while the meadow on the north is still called the Barbican. Terrible stories are told of the sufferings endured by followers of Stephen who had the misfortune to become prisoners here under Fitzcount's custody; and for one influential prisoner, William Martel, the new dungeon of Brien's Close was made, from which he was only released on condition of delivering up the Castle of Shirburn and its adjacent lands as a ransom. Throughout the war Wallingford Castle under its indomitable lord was the most powerful of all the strongholds of the empress; and it was here, in a meadow beneath the walls, that the war was ended, through the treaty proposed by the Earl of Arundel, granting the kingdom to Stephen for his life and the succession to the Empress's son, Henry Plantagenet.