John III of Sweden

John was born in 1537, son of Gustav I and his second wife Margaret Leijonhufvud, which made him half-brother to Erik XIV and full brother to the future Charles IX. He served as Duke of Finland from 1556, then led a rebellion that toppled Erik in 1569 and put himself on the Swedish throne - Erik's death followed under murky circumstances. His marriage to Catherine Jagiellon tied him to the Polish-Lithuanian dynasty; their son Sigismund would eventually rule both kingdoms. John ended the Northern Seven Years' War but dragged Sweden into a quarter-century struggle with Russia that brought minor territorial gains. Throughout his reign he pushed against the Lutheran current, attempting reunion with Rome over the resistance of his brother Duke Charles. He took the title Grand Duke of Finland in 1581. After Catherine's death in 1583, he remarried Gunilla Bielke in 1585. He died in 1592, having moved Sweden closer to Poland but no closer to the Pope.