From Canterbury the invading army advanced directly upon London, and took up a position in its neighbourhood. From this station a body of five hundred horsemen was sent forward to reconnoitre the approaches to the city, and the second battle of the conquest followed, if we may call that a battle which seems to have been merely one-sided. At any rate, the citizens intended to offer battle, and crossed the river and advanced against the enemy in regular formation, but the Norman knights made short work of the burgher battalions, and drove them back into the city with great slaughter. The suburb on the south bank of the Thames fell into the hands of the enemy, who burned down at least a part of it. William gained, however, no further success at this point. London was not yet ready to submit, and the river seems to have been an impassable barrier. To find a crossing the Norman march was continued up the river, the country suffering as before from the foraging of the army. The desired crossing was found at Wallingford, not far below Oxford and nearly fifty miles above London. That he could have crossed the river nearer the city than this, if he had wished, seems probable, and considerations of strategy may very likely have governed William's movements. Particularly might this be the case if he had learned that Edwin and Morcar, with their army, had abandoned the new king and retired northward, as some of the best of modern scholars have believed, though upon what is certainly not the best of evidence. If this was so, a little more time would surely convince the Londoners that submission was the best policy, and the best position for William to occupy would be between the city and this army in the north, a position which he could easily reach, as he did, from his crossing at Wallingford. If the earls had not abandoned London, this was still the best position, cutting them off from their own country and the city from the region whence reinforcements must come if they came at all. A long sweep about a hostile city was favourite strategy of William's.