King Harald V of Norway (10/10)

King Harald V of Norway holds the distinction of being one of the most inbred royals currently alive. His parents were first cousins, which significantly limited the number of unique great-grandparents he had. While most people have eight unique great-grandparents, Harald only has six. His grandmother and grandfather were not only siblings but also first cousins to each other. Further back in his ancestry, his great-grandmother, who appears twice, was the niece of his great-grandfather. This extensive inbreeding within Harald's lineage makes him the most inbred royal of the present time.