[Sidenote: Rivalry of Louis VII. and Henry II.] After the consolidation of the Angevin Empire, Louis had to watch narrowly the actions of a vassal more powerful than himself. Before long war became almost chronic between him and Henry. It was not that constant efforts were not made to secure peace and alliance. Henry married his eldest son to Louis’ daughter, Margaret, receiving as her marriage portion the long-coveted possession of the Vexin. In 1162 Louis VII. and Henry again made common cause in favour of Alexander III. against the Antipope [see page 257]. During his exile in France Alexander frequented the dominions of Henry as much as he did those of Louis. It was in Henry’s town of Tours that the council assembled that excommunicated the Antipope. Henry seemed too strong to make direct resistance of much avail. Before long Henry II. fell into his quarrel with Archbishop Thomas of Canterbury, which gave Louis an opportunity of adding to his rival’s difficulties, by giving as much support as he could to his enemies. After Thomas’s death Louis found an even better way of effecting this purpose by forcing Henry to divide his dominions among his sons, and then fomenting the discord that soon burst out between Henry and his wife and children. In 1170 the young Henry, Louis’ son-in-law, was crowned joint king with his father, after the French fashion. Geoffrey was already Duke of Brittany, and in 1172 Richard, the third son, was enthroned Duke of Aquitaine, and betrothed to Alice, Louis VII.’s younger daughter. Louis soon persuaded the vain and weak Henry III.—so he was often styled—to make common cause with him against his father. In 1173 a well-devised conspiracy burst forth against the power of Henry II. [Sidenote: The War of 1173 and 1174.] The feudal party in England and Normandy, the King of Scots, and Henry’s discontented vassals in Britain, made common cause with Louis VII. and the younger King Henry against the archenemy of the Capetian house. The vassals of France, who feared Henry more than Louis, joined the confederacy, and at their head were Geoffrey of Brittany and Richard of Aquitaine, and even Queen Eleanor herself. Among Louis’ greater vassals Philip of Alsace (son of Thierry of Alsace), Count of Flanders, entered into the league. So did the sons of Theobald the Great—Henry the Liberal, Count of Champagne, and Theobald V., the Good, Count of Blois, both married to Louis VII.’s daughters. The representative of the younger branch of Blois, the Count of Flanders’ brother, who ruled Boulogne as the husband of King Stephen’s daughter Mary, also took up the hereditary policy of his house. The good luck and the genius of Henry prevailed over Louis and his associates, and in 1174 peace was patched up on conditions that left matters much as they had been before the war. Eleanor of Aquitaine, captured as she was endeavouring to escape to her divorced husband’s court, was the chief sufferer. She was immured in a prison, from which