Christian II, the king of Denmark from 1513 - 1523, gives us a fascinating episode in Scandinavian History -- The "Bloodbath of Stockholm" (1520).
Christian was known as a "Tyrant" during his short reign, and if you ask the Swedes, they will tell you the same, as they refer to him as the "Wicked One."
Despite his fondness for the peasantry, and his need for all things German, Christian made many enemies in Sweden. Both the Danes and the Swedes held to a tenuous union (the Kalmar Union), but Christian's actions in November, 1520, would drive a permanent wedge between the two emerging nations.
The Danish army had successfully invaded Sweden and Christian II offered overtures of peace when he asked Swedish nobles, merchants, and even ordinary people into the castle at Stockholm. His plan was perhaps more diabolic -- he had prepared a large and lavish feast for his guests, just before he imprisoned them and began to "hunt" and "kill" them. Nearly 100 people would be hanged, beheaded, or in some other way murdered in Stockholm square.
It was Christian's pleasure to kill these men at will; for three days in stormy November there were people locked within the rooms of the castle. They had nowhere to go, and there was nowhere to hide where Christian would not find them. Only a spare handful of people would survive to tell the tale. Among them, it is notable -- and perhaps done on purpose by Christian -- that Gustav Eriksson Vasa would escape. He would later become the King of Sweden.