Both Absalon and Valdemar narrowly escaped assassination by Sweyn on this occasion, and escaped to Jutland, whither Sweyn followed them. Absalon probably did not take part in the following battle of Grathe Heath in 1157, where Sweyn was defeated and slain. This led to Valdemar ascending to the Danish throne. On Good Friday 1158, bishop died, and Absalon was eventually elected bishop of Roskilde on Zealand with the help of Valdemar, as the king's reward for Hvide family support. Bishop and advisor Absalon was a close counsellor of Valdemar, and chief promoter of the Danish crusades against the Wends. During the Danish civil war, Denmark had been open to coastal raids by the Wends. It was Absalon's intention to clear the Baltic Sea of the Wendish pirates who inhabited its southern littoral zone, which was later called Pomerania. The pirates had raided the Danish coasts during the civil war of Sweyn III, Canute V, and Valdemar, to the point where at the accession of Valdemar one-third of Denmark lay wasted and depopulated. Absalon formed a guardian fleet, built coastal defenses, and led several campaigns against the Wends. He even advocated forgiving the earlier enemies of Valdemar, which helped stabilize Denmark internally. Wendish campaigns The first expedition against the Wends conducted by Absalon in person, set out in 1160. These expeditions were successful, but brought no lasting victories. What started out as mere retribution, eventually evolved into full-fledged campaigns of expansion with religious motives. In 1164 began twenty years of crusades against the Wends, sometimes with the help of German duke Henry the Lion, sometimes in opposition to him. In 1168 the chief Wendish fortress at Arkona in Rügen, containing the sanctuary of their god Svantevit, was conquered. The Wends agreed to accept Danish suzerainty and the Christian religion at the same time. From Arkona, Absalon proceeded by sea to Charenza, in the midst of Rügen, the political capital of the Wends and an all but impregnable stronghold. But the unexpected fall of Arkona had terrified the garrison, which surrendered unconditionally at the first appearance of the Danish ships. Absalon, with only Bishop Sweyn of Aarhus and twelve "housecarls", thereupon disembarked, passed between a double row of Wendish warriors, 6000 strong, along the narrow path winding among the morasses, to the gates of the fortress, and, proceeding to the temple of the seven-headed god Rugievit, caused the idol to be hewn