The treaty with Roderic, if we accept it as Hoveden and Benedict have handed it down, shows that a full conquest of Ireland was not intended by Henry II. The possession of the port-towns gave him the command of St. George's Channel, and a control over the trade of the island. He had seen enough to know that a permanent conquest was beyond the power of a feudal army, and his policy was to balance the adventurers, his own creation De Lacy, and the native princes against each other. Fitz-Adelm, a subtle intriguer with an eye for money, probably seemed a fitter instrument for his purpose than any enterprising soldier. But Fitz-Adelm brought with him to Ireland one of those restless and unscrupulous men of action, who sometimes disconcert the best laid plans of statesmen. John De Courcy is represented by Giraldus as a tall, fair man, of immense strength and extraordinary audacity, an experienced warrior, though often more of a partisan than a general; but religious in his way, and ever ready to ascribe to God the glory of any successful exploit. He was the patron of the monk Jocelin, who wove such a tangled web about St. Patrick, and he carried with him everywhere a tract of St. Columba, which was supposed to point him out as the destined conqueror of Ulster. Seeing that neither gain nor glory could be had under the Viceroy, De Courcy, in January 1177, boldly marched into Ulster with twenty-two knights and 300 chosen men. Among the knights were Almaric St. Lawrence, ancestor of the Howth family, and Roger le Poer, apparently a collateral ancestor of the Powers and Eustaces. In the course of a year or two, though by no means always successful in battle, De Courcy made himself supreme in eastern Ulster. Where they had the advantage of the ground, the natives were too much for the adventurers; but in a fair field a hundred Normans, at least under such a leader as De Courcy, were more than a match for 1,000 Irish. Discipline and steadiness soon gave them the coast, and the castles which they built everywhere enabled them to make war or peace as they pleased. Downpatrick was John de Courcy's capital. [Sidenote: De Courcy and De Lacy. Castle-building.]