Queen Elizabeth & Prince Philip Were Third Cousins

When Queen Elizabeth II married Prince Philip in 1947, she wasn't just marrying a dashing naval officer—she was marrying her third cousin. Both were great-great-grandchildren of Queen Victoria, the monarch whose 63-year reign gave her ample time to earn the nickname "grandmother of Europe."

Elizabeth's lineage traced through Victoria's eldest son, King Edward VII, making her Victoria's great-great-granddaughter through the direct line of succession. Philip's connection was equally royal but came through a different branch: he descended from Victoria's second daughter, Princess Alice of Hesse, whose daughter Princess Alice of Battenberg was Philip's mother.

The Royal Family Tree Gets Complicated

But wait—there's more family overlap. Elizabeth and Philip were also second cousins once removed through King Christian IX of Denmark, known as the "father-in-law of Europe." European royalty in the 19th and early 20th centuries was essentially one big extended family reunion, with monarchs marrying cousins to strengthen political alliances and keep power within trusted bloodlines.

Queen Victoria had nine children, 42 grandchildren, and 87 great-grandchildren, creating a vast network of royal relatives across Europe. By the time World War I broke out, her descendants sat on the thrones of Britain, Germany, Russia, Spain, Norway, Romania, Sweden, and Greece.

Marrying Cousins: A Royal Tradition

Before anyone clutches their pearls, third cousins share only about 0.78% of their DNA—roughly the same genetic overlap as two random strangers. The practice of royal cousin marriage was less about genetics and more about geopolitics. Marrying within the royal club meant:

• Keeping wealth and titles in the family
• Creating political alliances between nations
• Ensuring your spouse understood the pressures of royal life
• Maintaining "pure" royal bloodlines (a concept that aged poorly)

Queen Victoria herself married her first cousin, Prince Albert, though their partnership became one of history's great love stories despite the family connection.

The Irony of World War I

The intertwined royal families created one of history's strangest footnotes: during World War I, Britain's King George V, Germany's Kaiser Wilhelm II, and Russia's Tsar Nicholas II were all first cousins—grandchildren of Queen Victoria. Family dinners must have been awkward after that whole global conflict thing.

Elizabeth and Philip's marriage proved more successful than most political arrangements. They were married for 73 years until Philip's death in 2021, making theirs the longest royal marriage in British history. They had four children, eight grandchildren, and twelve great-grandchildren—continuing Victoria's tradition of populating Europe's family trees, one royal baby at a time.