Most royal families in the world are related to each other either by blood or marriage. The European royal families are particularly intertwined, as they share a common ancestry dating back to the Middle Ages. For example, the British royal family is related to the Danish, Norwegian, Swedish, Belgian, Dutch, Spanish, and Luxembourgish royal families. The Spanish royal family is also related to the Portuguese royal family, while the Portuguese royal family is related to the Brazilian royal family. The Belgian royal family is also related to the Italian royal family, while the Italian royal family is related to the Albanian royal family. Additionally, the royal families of Monaco and Liechtenstein are related to several European royal families. Outside of Europe, the Japanese imperial family is related to the Bhutanese royal family, while the Moroccan royal family is related to the Saudi Arabian royal family. Overall, it is estimated that over 200 royal families worldwide are related to each other either by blood or marriage.