This prince, whose dominions confined on France and Normandy, was usually courted for an ally by both Kings in their several quarrels; but having little faith or honour, he never scrupled to change sides as often as he saw or conceived it for his advantage. After the great victory over the French, he closed in with King Henry, and gave his daughter to the young prince William; yet at the same time, by the private encouragement of Louis, he prevailed on the King of England to be easy in the conditions of a peace. Upon the unfortunate loss of the prince, and the troubles in Normandy thereupon, he fell again from the King, gave his other daughter to William the son of Robert, and struck up with France to take that prince again into protection. But dying soon after, and leaving his son Geoffrey to succeed in that earldom, the King was of opinion he could not anywhere bestow his daughter with more advantage, both for the security and enlargement of his dominions, than by giving her to this earl; by which marriage Anjou would become an acquisition to Normandy, and this be a more equal match to so formidable a neighbour as France. In a short time the marriage was concluded; and this Earl Geoffrey had the honour to introduce into the royal family of England the surname of Plantagenet, borne by so many succeeding Kings, which began with Henry II. who was the eldest son of this marriage. But the King of France was in great discontent at this match: he easily foresaw the dismal consequences to himself and his successors from such an increase of dominion united to the crown of England: he knew what impressions might be made in future times to the shaking of his throne by an aspiring and warlike king, if they should happen in a weak reign, or upon any great discontents in that kingdom. Which conjectures being highly reasonable (and since often verified by events) he cast about to find some way of driving the King of England entirely out of France; but having neither pretext nor stomach in the midst of a peace to begin an open and formal quarrel, there fell out an accident which gave him plausible occasion of pursuing his design. Charles the Good Earl of Flanders having been lately murdered by some of his subjects, upon private revenge, the King of France went in person to take revenge of the assassins; which he performed with great justice and honour. But the late earl leaving no heir of his body, and several competitors appearing to dispute the succession, Louis rejected some others who seemed to have a fairer title, and adjudged it to William the son of Robert, the better to secure him to his interests upon any design he might engage in against the King of England. Not content with this, he assisted the Earl in person, subdued his rivals, and left him in peaceable possession of his new dominion.