Frederick I of Denmark

Born in 1471, the youngest son of Christian I, Frederick wasn't meant to be king - he was handed joint rule of Schleswig and Holstein in 1490 and settled into Gottorf Castle. When his brother Hans died in 1513, he declined the crown; when Hans's son Christian II proved intolerable to the nobility, Frederick accepted election in 1523 and fought his way to victory by 1524, bound by a coronation charter so restrictive it became legendary. His reign was a long defensive crouch: Christian II, backed by Emperor Charles V, kept trying to reclaim the throne, sparking a rising in Blekinge in 1525 and an invasion via Norway in 1531 that Frederick's forces eventually crushed, capturing Christian in 1532. Officially Catholic, Frederick quietly sheltered Lutheran preachers like Hans Tausen and aligned with Protestant Hesse and Saxony, playing confessional tensions to keep nobles and bishops in check. He died at Gottorp in 1533, and the balance died with him - his death triggered the Count's Feud, a succession war that ended with his son Christian III on the throne and Lutheranism installed as state religion.