It needs little imagination to picture the encounter of the two hosts, clad and armed substantially in the same fashion, practically of the same race. After a desperate hand-to-hand conflict the English prevailed; Harold Hardrada and Tostig were both killed, and the host of the Northmen was almost annihilated. With politic mercy Harold allowed his namesake's youthful son and the remnant of the invaders to sail home, on their giving pledges for peace, which in truth they were long in no condition to break. The victory of Stamford Bridge was a great stroke for the security of Europe generally: it broke for ever the aggressive power of the Northmen, which for two centuries had been a standing danger to all coasts from the mouth of the Baltic to far into the Mediterranean, and which had completely conquered two regions as far remote from each other as Sicily and Normandy. At the same time the fearful losses of the battle may well have turned the scale in the struggle that was impending with the transformed Northmen from across the Channel. William of Normandy's fleet and army was assembled in the first instance at the mouth of the Dive, west of the Seine. Of its numbers it is impossible to speak with confidence, the accounts vary so greatly; but it was as large and complete as the resources of his duchy and the promises he held out to adventurers could make it. He was ready to sail some time in August, but the wind was steadily contrary. About the time when the English fleet was perforce withdrawn from the Channel, he was able to move his whole expedition to the mouth of the Somme, a necessary preliminary to attempting to cross the Channel. So large a fleet, consisting no doubt to a great extent of open boats, could not possibly have ventured to make the passage from the original point of assembly, which was doubtless selected as being more central to Normandy generally. Not for two or three weeks more did the necessary south wind blow. On September 27 the wind was at last favourable: next day William landed at Pevensey, and on the 29th occupied Hastings, where he formed a fortified camp to protect his ships. Nothing could have been more opportune for his interests: he had been unable to move while the English fleet was at sea, nor until Harold, far away in the north, had been weakened by the slaughter among his housecarls at Stamford Bridge. It was not the Norman's policy to plunge into a hostile country. Harold must needs come to meet him, and the nearer he could bring on a battle to his fleet, and therefore to his means of escape in case of defeat, the better for him. Accordingly he remained at Hastings, ravaging the country far and wide, partly for subsistence, partly to compel Harold to approach him.