Henry the Lion sought to rule within his duchies with the same autocratic power with which he governed his border conquests. The local nobles and prelates saw in his policy a design against their franchises, and combined to offer him a vigorous resistance. Albert the Bear, who had never lost hope of regaining Saxony, opposed him even in the Marks. In 1166 the princes of Saxony, headed by Rainald of Dassel and the Archbishop of Bremen, went to open war against Henry, but the personal intervention of the Emperor restored peace in the Diet of Würzburg. The Lion’s northern allies were equally alarmed at his triumphs; and Valdemar of Denmark, irritated by his requiring a share in the recent Danish conquest of Rügen, became his enemy, but was soon obliged to crave his forgiveness, and Valdemar’s son and successor, Canute VI., married Henry’s daughter Gertrude. In 1170 the death of the restless Margrave Albert relieved Henry from the most dangerous of his opponents. His position was now so strong that he was able, between 1170 and 1172, to go on pilgrimage to the Holy Land, where he was received with great honour, and whence he brought back many relics, which he enshrined in the stately churches at Brunswick of which he was the founder. Though shorn of the East Mark by the creation of the new duchy of Austria, Henry was still able to exercise almost as great an influence on the Germanisation of the south-west as on the same process in the north-east. It was the age of German colonisation, when, from the overpeopled lands of the Netherlands and old Saxony, adventurers sought a fresh home in the lands newly won to civilisation. German colonists in Meissen and in the lands ruled by Czech and Magyar, owed their position to Henry. In Bavaria itself he was the founder of the city of Munich. It was inevitable that Frederick should look with suspicion upon so powerful and restless a vassal, especially as, even before the Chiavenna interview, Henry had ceased to take part in promoting the imperial designs on Italy. But as long as Frederick’s main object was the subjection of the Church and the Lombards, the support of Henry was indispensable to him. However, after the Peace of Venice the condition of affairs was altered. Henceforth the Emperor’s best hopes of success, both in Germany and Italy, lay in the support of the great ecclesiastics who had so long opposed Henry in Saxony. It was now Frederick’s policy to strengthen his position in North Germany by alliances with the local magnates, both ecclesiastical and lay, who were eager to join with the Emperor in breaking down the power of their autocratic duke.