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.
Counts of Stade The Counts of Stade were members of the Saxony nobility beginning in the 10th century. Stade had developed since the 8th century as a principal center of trade and communications. The Counts of Stade created their domain between the lower Elbe and Weser rivers. They extended their power northwards with the acquisition of Dithmarschen in the 11th century. They became the Margraves of the Nordmark (Northern March) in 1056. There is also a close political and familial relationship between the Counts of Stade and the Counts of Walbeck. The county of Stade and Northern March were replaced by the March of Brandenburg by Henry the Lion, Duke of Saxony, in the 12th century. The family of Counts of Stade is referred to as the House of Udonids.