Lanfranc was the first abbot of the latter; and when William became king of England, Lanfranc was made archbishop of Canterbury and primate of the Church of England, as well as privy counsellor of his king.

William excelled in the art, so essential to government, of promptly recognizing the worth of men, and of appropriating their influence to himself whilst exerting his own over them.
About the same time he gave his contemporaries, princes and peoples, new proofs of his ability and power.

Henry I., king of France, growing more and more disquieted at and jealous of the duke of Normandy's ascendency, secretly excited against him opposition and even revolt in his dominions.
These dealings led to open war between the suzerain and the vassal, and the war concluded with two battles won by William, one at Mortemer near Neuchatel in Bray, the other at Varaville near Troarrh "After which," said William himself, "King Henry never passed a night tranquilly on my ground." In 1059 peace was concluded between the two princes.

Henry I.
died almost immediately afterwards, and on the 25th of August, 1060, his son Philip I.succeeded him, under the regency of Baldwin, count of Flanders, father of the Duchess Matilda.

Duke William was present in state at the coronation of the new king of France, lent him effectual assistance against the revolts which took place in Gascony, reentered Normandy for the purpose of holding at Caen, in 1061, the Estates of his duchy, and at that time published the famous decree observed long after him, under the name of the law of curfew, which ordered "that every evening the bell should be rung in all parishes to warn every one to prayer, and house-closing, and no more running about the streets." The passion for orderliness in his dominion did not cool his ardor for conquest.