Charles Frederick, Duke of Schleswig-Holstein-Gottorp was a Prince of Sweden and Duke of Schleswig-Holstein-Gottorp and an important member of European royalty. His dynasty, the Dukes of Schleswig-Holstein-Gottorp, were a cadet branch of the ancient House of Oldenburg, which at that time was ruling Denmark-Norway. His mother was a sister of Charles XII of Sweden. Charles Frederick married a daughter of Peter the Great and became the father of the future Peter III of Russia. As such, he is the progenitor of the Russian imperial house of Holstein-Gottorp-Romanov and the patrilineal ancestor of all Russian emperors starting with Peter III, except for Catherine II.

The House of Oldenburg is an ancient dynasty of German origin whose members rule or have ruled in Denmark, Iceland, Greece, Norway, Russia, Sweden, the United Kingdom, Livonia, Schleswig, Holstein, and Oldenburg. The current King of the United Kingdom and King of Norway are agnatic members of this house, meanwhile the King of Spain and King of Denmark are matrilineal members.