The Duchy of Holstein was established by a Scandinavian monarch under what union?
Duchy of Holstein The Duchy of Holstein (German: "Herzogtum Holstein" , Danish: "Hertugdømmet Holsten" ) was the northernmost state of the Holy Roman Empire, located in the present German state of Schleswig-Holstein. It was established when King Christian I of Denmark had his County of Holstein-Rendsburg elevated to a duchy by Emperor Frederick III in 1474. Holstein was ruled jointly with the Duchy of Schleswig by members of the Danish House of Oldenburg for its entire existence.
Eric XIV of Sweden Eric XIV (Swedish: "Erik XIV" ; 13 December 1533 – 26 February 1577) was King of Sweden from 1560 until he was deposed in 1568. Eric XIV was the eldest son of Gustav I (1496–1560) and Catherine of Saxe-Lauenburg (1513–35). He was also ruler of Estonia, after its conquest by Sweden in 1561.