Frederick II of Denmark

Frederick II significantly expanded the Danish navy, building new warships and strengthening naval infrastructure. This investment made Denmark a major naval power in the Baltic Sea during his reign.

Frederick II led Denmark into the Northern Seven Years' War against Sweden. The war was inconclusive, ending with the Treaty of Stettin in 1570, which confirmed the status quo but drained Danish resources.

Frederick II signed the Treaty of Stettin ending the Northern Seven Years' War. The treaty maintained the territorial boundaries but required Sweden to pay a ransom for the fortress of

Frederick II commissioned the construction of Kronborg Castle in Helsing