Waldemar IV (ca. 1320-1375) reunited the kingdom of Denmark under his rule, presenting a strong, nationalistic challenge to the mercantile Hanseatic League.

Waldemar IV was born to a bankrupt crown. In 1320, the year he was born, his father, King Christoffer II, was trading royal power to Denmark's nobles and clergy in an effort to maintain his rule. It was a narrow balancing act that had Christoffer II and his predecessors spending Denmark's wealth and their political resources on fruitless wars within their realm and military campaigns against their own nobility. At the time of Waldemar's birth, the state's creditors were demanding payment.

The province of Holstein, one of the wealthiest within the Danish realm, had become one of the leading lenders to the king's court. By 1326, Count Gert of Holstein, had amassed enough wealth and power that he schemed to replace the king with an underage pretender, Valdemar...