Her Majesty Queen Elizabeth II and His Royal Highness Prince Philip, Duke of Edinburgh have been married for 71 years, but their relationship goes much farther back. In fact, they knew each other from childhood—and are cousins.

How Queen Elizabeth II and Prince Philip Are Secretly RelatedShutterstock

Historically, marriage among royals wasn’t so much about love as it was about strengthening alliances for political gain, which could be achieved most conveniently through marriages arranged between members of European dynasties. What was also achieved, however, whether intentionally or not, was that most of Europe’s royal families now share common ancestors.

That’s why it’s really not surprising that Her Majesty Queen Elizabeth and His Royal Highness Prince Philip, Duke of Edinburgh are not only cousins, but cousins through more than one line of descent. Here’s how the two royal lovebirds, whose marriage was not arranged by their families, are related:

Both are great-great-grandchildren of Queen Victoria:

  • Queen Elizabeth: Queen Elizabeth was born Princess Elizabeth Alexandra Mary in 1926, the eldest child of then-Prince Albert (later, King George VI), who was the second son of King George V, who was the second son of King Edward VII, who was Queen Victoria’s second child. Find out 11 more fascinating facts about Queen Elizabeth.
  • Prince Phillip: Prince Philip was born Prince Philip of Denmark and Greece in 1921 to Princess Alice of Battenberg, whose mother was Princess Victoria of Hesse, whose mother was Princess Alice, who was Queen Victoria’s third child. Here is why Prince Philip is not the King of England.

Having had the same great-great-grandmother (Queen Victoria), Elizabeth (the progeny of Victoria’s son, King Edward VII) and Philip (the progeny of Victoria’s daughter, Princess Alice) are third cousins. Check out these 23 rarely seen photos of the royal family.

Prince Philip and the Queen are also related through King Christian IX of Denmark:

  • Queen Elizabeth: Christian IX was the great-great-grandfather of Queen Elizabeth II. Elizabeth’s father was George VI, who was the son of George V, who was the son of Alexandra of Denmark (who was married to King Edward VII, the son of Queen Victoria), who was the daughter of Christian IX.
  • Prince Philip: King Christian IX of Denmark was Prince Philip’s paternal great-grandfather. Philip’s father was Prince Andrew of Greece and Denmark, who was the son of Prince George I of Greece, who was the son of Christian IX.

To put it another way, Prince Philip had the same great-grandfather as Queen Elizabeth’s father, George VI, making Philip and Elizabeth second cousins once removed.

Next, don’t miss these sentimental photos of Queen Elizabeth II and Prince Philip.