There is a passage in Domesday Book which gives us a fair idea of the size of the town in the Conquerors day. It contained over seven hundred houses, but of these, so harshly had the Normans treated the place, two-thirds were ruined and unable to pay taxes. William made Robert D'Oily, one of his followers, governor of Oxford. D'Oily's is the earliest hand (a heavy one, by the way, as the townsfolk learnt to their cost) whose impress is visible on the Oxford of to-day. We may indeed, if we please, attribute a certain piece of wall in the Cathedral to a remoter date, but the grim old tower (which appears in the first illustration) is the first building in Oxford whose author can with certainty be named. It is all that remains of the Castle which Robert D'Oily built in order to control the surrounding country; and he built his stronghold by the riverside because he thereby dominated the waterway, along which enemies were apt to come, as well as wide tracts of land in every direction. No doubt the hands of the conquered English laboured at the massive structure which was to keep them in subjection. [Illustration: 0023] [Illustration: 0024] A queen was once besieged in the castle, Matilda, Henry I.'s daughter. When food gave out she made her escape in a romantic manner, so the story tells. The river was frozen and the ground covered with snow. The queen was let down from the tower by night with ropes, clad in white, the better to escape observation. Three knights were with her, clad in white also, under whose guidance she reached Wallingford on foot, and so escaped King Stephen's clutches. To the period of the Norman Conquest belongs also the tower of St. Michaels Church, in the Cornmarket. It has been usual to describe this edifice as Saxon; but antiquaries incline to think that if Robert D'Oily did not build St. Michael's tower, he at least repaired it. This tower formed a part of the city wall, and from its narrow windows arrows may have rained upon advancing foes. Adjoining it was Bocardo, the old north-gate of the city, whose upper chamber was long used as a prison. Nothing of Bocardo now remains; but Robert D'Oily's handiwork is traceable, as many think, in the crypt and chancel of St. Peter-in-the-East and in the chancel arch at Holywell. In these buildings, then, the history of Norman Oxford is written, so far as history can be written in stone; yet here and there about the city are to be seen structures which, although two or three centuries younger, have an appearance hardly less venerable. Year after year the aged walls and portals are thronged with fresh generations of the youth of England; and it is in this combination of youth and age that no little of the charm of Oxford lies. We speak within the limitations of mortality: but, could we escape them for a moment, "immortal age beside immortal youth" might be her most appropriate description.