I traced my ancestry back to royalty in Europe. The first queen and king I came upon were Queen Maud (Countess of Huntingdon) and King David I of Scotland. Reign: 1124-1153 AD.
King David's father King Malcolm III and grandfather King Duncan were major characters in Shakespeare's Macbeth, which is based on real history.
Queen Maud's grandfather Siward, Earl of Northumbria and York, was also a major figure; his army killed Macbeth and restored Malcolm to the throne.
Siward's line from Scandinavia had a legedary claim of being descended from a polar bear.
David's mother Saint Margaret was one of the last surviving members of the House of Wessex, the last royal Anglo-Saxons before the Norman conquest of 1066.
Maud's great-uncle was William the Conqueror, the first Norman ruler of England. That line was descended from Charlemagne, Holy Roman Emperor.
Maud and David's daughter-in-law Ada de Warenne was similarly descended from Charlemagne by way of French kings. Ada was also descended from the pre-Russian kingdom called Kievan Rus.
Ada's great-great-grandmother was Ingegard Olofsdottir, grand princess of Kievan Rus, originally from Sweden and descended from the legendary Viking Skagul Toste and from his daughter Sigrid the Haughty.
Ingegard, her husband King Yaroslav the Wise, and her father Olof Skotkunung, all helped save the life of Saint Margaret's father, which allowed the survival of the House of Wessex.