Adolf IV won several victories against the
Danes. In 1225 he won the
Battle of Mölln against
Albert II, Count of Weimar-Orlamünde. On 22 July 1227 with his coalition army Adolf was victorious in the
Battle of Bornhöved against King
Valdemar II of Denmark with his Danish army and German allies (the Welfs), and thus regained Holstein. In 1235 he founded
Kiel and in 1238
Itzehoe. In 1238 he took part in a crusade in
Livonia. In fulfilment of an oath taken during the heat of the Battle of Bornhöved, Adolf withdrew in 1238 to a
Franciscan friary and in 1244 was ordained a priest in Rome (his two under-age sons passed into the guardianship of his son-in-law
Duke Abel of Schleswig). Also in 1244 he founded
Neustadt in Holstein. He died in 1261 in the Franciscan friary in Kiel, which he himself had founded, whereupon Holstein was divided between his sons John (of Holstein-Kiel) and Gerhard (of Holstein-Itzehoe). ==Marriage and issue==