The Duchy of Holstein was established by a Scandinavian monarch under what union?
Christian I of Denmark Christian I (February 1426 – 21 May 1481) was a Scandinavian monarch under the Kalmar Union. He was King of Denmark (1448–1481), Norway (1450–1481) and Sweden (1457–1464). From 1460 to 1481, he was also Duke of Schleswig (within Denmark) and Count (after 1474, Duke) of Holstein (within the Holy Roman Empire). He was the first Danish monarch of the House of Oldenburg.
Duchy of Livonia The Duchy of Livonia (Polish: "Księstwo Inflanckie" ; Lithuanian: "Livonijos kunigaikštystė" ; Latin: "Ducatus Ultradunensis" ; Estonian: "Üleväina-Liivimaa hertsogkond" ; Latvian: "Pārdaugavas hercogiste" ; also referred to as Polish Livonia or Inflanty) was a territory of the Grand Duchy of Lithuania—and later the Polish–Lithuanian Commonwealth—that existed from 1561 to 1621. It corresponds to the present-day areas of northern Latvia and southern Estonia.