Christian II was a king who ruled over Denmark, Norway, and Sweden during the early 16th century. He became king of Denmark in 1513 and later claimed the throne of Sweden. His reign was marked by attempts to centralize power and reform the government, but he faced significant opposition from the nobility and other factions. In 1520, Christian II was involved in the infamous Stockholm Bloodbath, where many of his political opponents were executed. This event led to his downfall, and he was eventually deposed in 1523. After his exile, he spent many years trying to regain his throne but was never successful.