As soon as the frost broke up Count Bossu, who had been building a fleet of small vessels in Amsterdam, cut a breach through the dyke and entered the lake, thus entirely cutting off communications. The Prince of Orange on his part was building ships at the other end of the lake, and was doing all in his power for the relief of the city. He was anxiously waiting the arrival of troops from Germany or France, and doing his best with such volunteers as he could raise. These, however, were not numerous; for the Dutch, although ready to fight to the death for the defence of their own cities and families, had not yet acquired a national spirit, and all the efforts of the prince failed to induce them to combine for any general object. His principal aim now was to cut the road along the dyke which connected Amsterdam with the country round it. Could he succeed in doing this, Amsterdam would be as completely cut off as was Haarlem, and that city, as well as the Spanish army, would speedily be starved out. Alva himself was fully aware of this danger, and wrote to the king: "Since I came into this world I have never been in such anxiety. If they should succeed in cutting off communication along the dykes we should have to raise the siege of Haarlem, to surrender, hands crossed, or to starve." The prince, unable to gather sufficient men for this attempt, sent orders to Sonoy, who commanded the small army in the north of Holland, to attack the dyke between the Diemar Lake and the Y, to open the sluices, and break through the dyke, by which means much of the country round Haarlem would be flooded. Sonoy crossed the Y in boats, seized the dyke, opened the sluices, and began the work of cutting it through. Leaving his men so engaged, Sonoy went to Edam to fetch up reinforcements. While he was away a large force from Amsterdam came up, some marching along the causeway and some in boats. A fierce contest took place, the contending parties fighting partly in boats, partly on the slippery causeway, that was wide enough but for two men to stand abreast, partly in the water. But the number of the assailants was too great, and the Dutch, after fighting gallantly, lost heart and retired just as Sonoy, whose volunteers from Edam had refused to follow him, arrived alone in a little boat. He tried in vain to rally them, but was swept away by the rush of fugitives, many of whom were, however, able to gain their boats and make their retreat, thanks to the valour of John Haring of Horn, who took his station on the dyke, and, armed with sword and shield, actually kept in check a thousand of the enemy for a time long enough to have enabled the Dutch to rally had they been disposed to do so. But it was too late; and they had enough of fighting. However, he held his post until many had made good their retreat, and then, plunging into the sea, swam off to the boats and effected his escape. A braver feat of arms was never accomplished.