Henry of England was equally active on his side. Besides his Breton vassals, he could rely upon the special enemies of Louis, the barons of the Isle de France. He became a warm partisan of Thierry of Alsace, and intrigued with the Flemish townsfolk, who were seldom on good terms with their counts. [Sidenote: Louis VI. and the House of Blois.] Above all he had the powerful support of his nephews, Theobald IV., Count of Blois, surnamed the Great, and of his younger brother Stephen, who through his wife had become Count of Boulogne, and was later to become King of England. Theobald the Great was a much abler man than his brother, and the most rancorous and persistent of Louis VI.’s foes among the leading feudatories. In 1125 he once more united the counties of Blois and Champagne, so that he could attack his suzerain both from the south and from the east. But the most powerful combinations of twelfth century diplomacy proved singularly weak when brought into action. Almost ceaseless war was waged between Louis and Theobald, and the struggles of Louis and Henry were only less constant. The desolating, unending, purposeless, and unskilful warfare of the twelfth century was utterly fruitless in results. It was enough for Louis that, despite some defeats, he held his own fairly well. [Sidenote: Louis VI. and Aquitaine.] Before the end of Louis’ reign new complications ensued. In 1128, finding the hostility of Anjou a chief obstacle in the way of his plans, Henry I. married his widowed daughter and heiress, the Empress Matilda, to Geoffrey, the son and heir of his old enemy Fulk of Anjou. The way was thus prepared for the Angevin Empire of Henry II., though the refusal of England to accept Matilda as Henry’s successor in 1135 seemed for the moment to remove any imminent danger. While England received Stephen, Geoffrey of Anjou established himself a few years later as duke of Normandy. Soon after, Stephen’s brother, Theobald of Blois, made his peace with Louis. Moreover, two years later Louis negotiated another alliance that seemed to offer even greater prospects to the heir to the French throne. On Good Friday 1137 William X., Count of Poitou and Duke of Aquitaine, died on pilgrimage. He was the last male of his house, and his daughter Eleanor succeeded peaceably to his great inheritance. William had wished that his daughter should marry Louis the Young, the eldest surviving son of his suzerain. In a few months the marriage was effected. The vast domains of Eleanor in Poitou, Saintonge, and Guienne at once doubled the domain of the crown, and made the young Louis immediate lord of most of the great barons between the Loire and the Pyrenees. But so long as the interests and feelings of south and north were so absolutely different, it was no great gain to a king, who had only just secured the overthrow of the feudal castles of the Seine and Oise, to begin in his old age a similar but more hopeless struggle on the Charente and the Dordogne.