(in progress)
After the unexpected death of Christopher of Bavaria in 1448, there was some question about who should succeed him. The Danish crown was an elective monarchy, although the nearest male heir was customarily chosen. Christopher was the last direct descendant of Valdemar IV, so there were no obvious choices as the nearest male relative.
With many possible candidates, the Council of the Realm first offered the throne to Duke Adolphus of Schleswig (or Slesvig) because the most prominent lord in the Danish kingdom, but because he was childless he declined and suggested his nephew Count Christian of Oldenburg. The Council offered the throne to Christian under a number of conditions: Christian had to promise to obey the accession promissory of Valdemar III, which states that no one could be both the king of Denmark and the duke of Schleswig, that he would rule as a just king and that he would marry Dorothea of Brandenburg, the widow of his predecessor Christopher III.