Christina of Sweden was a 17th-century monarch who ruled as a king. Born covered in hair, she had a cry so deep that everyone thought she was a boy. Happy to learn she was a girl, her father decreed she would have the education of a prince and made her his heir. She inherited the throne at the age of 6 and ruled for years as a blunt, unmarried, lady king who often disguised herself as a man for political and safety reasons. Source Source 2