But Stephen, in the words of his panegyrist, had "awaked as one out of sleep." Summoning to his standard his friends and supporters, he marched on Gloucestershire itself, and appeared unexpectedly at Cirencester on the line of the enemy's communications. Its castle, taken by surprise, was burnt and razed to the ground. Then, completing the isolation of the Empress, by storming, as he advanced, other of her posts,[608] he arrived before the walls of Oxford on the 26th of September.[609] The forces of the Empress at once deployed on the left bank of the river. The action which followed was a curious anticipation of the struggle at Boyne Water (1690). The king, informed of the existence of a ford, boldly plunged into the water, and, half fording, half swimming, was one of the first to reach the shore. Instantly charging the enemy's line, he forced the portion opposed to him back towards the walls of the city, and when the bulk of his forces had followed him across, the whole line was put to flight, his victorious troops entering the gates pell-mell with the routed fugitives. The torch was as familiar as the sword to the soldier of the Norman age, and Oxford was quickly buried in a sheet of smoke and fire.[610] The castle, then of great strength, alone held out. From the summit of its mound the Empress must have witnessed the rout of her followers; within its walls she was now destined to stand a weary siege. It is probable that Stephen's success at Oxford was in part owing to the desertion of the Empress by those who had sworn to defend her. For we read that they were led by shame to talk of advancing to her relief.[611] The project, however, came to nothing, and Earl Robert, hearing of the critical state of affairs, became eager to return to the assistance of his sister and her beleaguered followers. Geoffrey of Anjou had, on various pretences, detained the earl in Normandy, instead of accepting his invitation and returning with him to England. But Robert's patience was now exhausted, and, bringing with him, instead of Geoffrey, the youthful Henry "fitz Empress," he sailed for England with a fleet of more than fifty ships. Such was the first visit to this land of the future Henry II., being then nine years and a half, not (as stated by Dr. Stubbs) eight years old.[612]