The Danish navy, led by among other militaries, Archbishop Absalon, conquered and destroyed the fortress of Cape Arkona.
Jaromar, who was not committed to hitherto pagan rulers of the island, accepted Christianity and promised loyalty to King Valdemar I of Denmark.
[2] Jaromar allied with the Hvide and Galen magnate clans, who were leaders of Zealand and Skåne.
Jaromar had his son and heir Wizlaw I marry a lady from these Danish magnates' families, who were influential in those parts of Denmark that were closest to Rügen.
By 1185, Jaromar I had started construction of St. Mary's Church (Marienkirche) erected in his stronghold Rugard (which later became the town Bergen-auf-Rügen).