The great vassals, on the other hand, acted on the theory that the king was simply their feudal lord. As for the king himself, he accepted both views of his position and made use both of the older theory of kingship and of his feudal suzerainty to secure more and more control over his realms. For over three hundred years the direct male line of the Capetians never once failed. It rarely happened, moreover, that the crown was left in the weak hands of a child. By the opening of the fourteenth century there was no doubt that the king, and not the feudal lords, was destined to prevail. [Sidenote: Louis the Fat, 1108-1137.] [Sidenote: Philip Augustus, 1180-1223.] The first of the kings of France to undertake with success the serious task of conquering his own duchy was Louis the Fat (1108-1137). He was an active soldier and strove to keep free the means of communication between the different centers of his somewhat scattered feudal domains and to destroy the power of the usurping castellans in his fortresses. But he made only a beginning; it was reserved for his famous grandson, Philip Augustus (1180-1223), to make the duchy of France into a real kingdom. [Sidenote: The Plantagenets in France.] [Sidenote: Henry II.] 49. Philip had a far more difficult problem to face than any of the preceding kings of his house. Before his accession a series of those royal marriages which until recently exercised so great an influence upon political history, had brought most of the great fiefs of central, western, and southern France into the hands of the king of England, Henry II, who now ruled over the most extensive realm in western Europe. Henry II was the son of William the Conqueror's granddaughter Matilda,[78] who had married one of the great vassals of the French kings, the count of Anjou and Maine.[79] Henry, therefore, inherited through his mother all the possessions of the Norman kings of England,--namely, England, the duchy of Normandy, and the suzerainty over Brittany,--and through his father the counties of Maine and Anjou. Lastly, through his own marriage with Eleanor, the heiress of the dukes of Guienne (as Aquitaine was now called), he possessed himself of pretty much all of southern France, including Poitou and Gascony. Henry II, in spite of his great importance in English history, was as much French as English, both by birth and sympathies, and gave more than half his time and attention to his French possessions. [Sidenote: Philip and the Plantagenets.]