Who was the Danish king who entered the war in 1625?

Christian IV was the Danish king who entered the Thirty Years’ War in 1625.

Christian IV ruled Denmark and Norway from 1588 until his death in 1648. He intervened as a Protestant leader and as Duke of Holstein, whose territories were connected to the political and military struggles of the Holy Roman Empire. He also wanted to protect Danish influence over the Elbe and Weser rivers and secure positions in northern Germany for his family.

Christian entered the conflict on 9 May 1625, leading an army associated with the Lower Saxon Circle. His campaign initially threatened the imperial position, but the imperial commander Count Tilly defeated him at the Battle of Lutter in 1626. Imperial and Catholic League forces later occupied much of Jutland.

The Danish intervention ended with the Treaty of Lübeck in 1629. Christian kept his territories but agreed not to intervene further in the war. Gustavus Adolphus of Sweden, another famous Protestant ruler, entered the conflict later, in 1630. Frederick III was Christian’s successor, while Philip IV was king of Spain.