But to return to Robert D'Oigli, the Conqueror's Castellan. From what little we know of him, he would appear to have been a typical Norman baron, ruthless, yet superstitious, strong to conquer and strong to hold. Very much the rough, marauding soldier, but gifted with an instinct for government and order, he came over to the conquest of England in the train of William the Bastard and in the company of Roger D'Ivry, his sworn brother, to whom, as the chronicler tells us, he was "iconfederyd and ibownde by faith and sacrament." Oxfordshire was committed to his charge by the Conqueror, to reduce to final subjection and order. He seems to have ruled it in rude soldierly fashion, enforcing order, tripling the taxation of the town and pillaging without scruple the religious houses of the neighbourhood. For it was only by such ruthless exaction that the work which William had [Illustration: BIRD'S-EYE VIEW OF OXFORD BY RALPH AGAS (1578): FROM THE ENGRAVING BY WHITTLESEY (1728).] set him to do could be done. He had indeed been amply provided for, so far as he himself was concerned, by the Conqueror, chiefly through a marriage with a daughter of Wiggod of Wallingford, who had been cupbearer to Edward the Confessor; but money was needed for the great fortress which was now to be built to hold the town, after the fashion of the Normans, and by holding the town to secure, as we have said, the river. "In the year 1071," it is recorded in the Chronicle of Osney Abbey, "was built the Castle of Oxford by Robert D'Oigli." And by the Castle we must understand not the mound which was already there, nor such a castle as was afterwards built in the twelfth and thirteenth centuries, but at least the great tower of stone which still exists and was intended to guard the western approach to the Castle. S. George's tower, for so it was called because it was joined to the chapel of S. George's College within the precincts, was upon the line of the enceinte. The walls are eight feet four inches thick at the bottom, though not more than four feet at the top. The doorway, which is some twelve feet from the ground, was on the level of the vallum or wall of fortification, and gave access to the first floor. There are traces of six doorways above the lead roof, which gave access to the "hourdes." These were wooden hoardings or galleries that could be put up outside. They had holes for the crossbows, and holes for the pouring down of stones, boiling pitch or oil on to the heads of threatening sappers. They were probably stored in the top room of the tower, which is windowless. The construction of the staircase of the tower is very peculiar. Ascend it and you will obtain a magnificent view of Oxford, of Iffley and Sandford Lock, Shotover and the Chiltern Hills, Hincksey, Portmeadow, Godstow, Woodstock and Wytham Woods.