Royal families around the world once had some pretty strict rules about who their heirs could and could not marry. They wanted to maintain the purity of a lineage, and for centuries, that meant marrying within a family.
To most people, this seems like a deeply antiquated practice. No longer are royals bound to these limited parameters of who they can marry, after all. Still, there are a surprising number of couples who are modern examples of the practice.
How does it happen? The circles of aristocracy and royalty are small. These families all have histories with each other that twist and turn throughout time. As a result, it's still easier than you think for a royal to marry a relation.
Empress Elisabeth of Austria and Franz Joseph I
Empress Elisabeth was born into the royal Bavarian House of Wittelsbach. She became queen of Hungary when she married her first cousin, Emperor Franz Joseph I, when she was 16 years old. He was the intended suitor of her older sister, Helene, but the two were uncomfortable around each other. Franz became infatuated with Elisabeth, although it's believed she didn't feel the same.
King George IV and Caroline of Brunswick
George IV and Caroline of Brunswick were first cousins who were arranged in a marriage. At the time, George IV was already a decade into an illegal marriage. George and Caroline were unhappy, and their marriage resulted in just one child, who died during childbirth.
Queen Victoria and Prince Albert
Queen Victoria married her first cousin, Prince Albert, in order to keep peace between royal families and strengthen borders. It was Victoria who proposed the marriage as a strategic measure. They grew to have a great love, but they were both pretty indifferent about it at the start.
King Edward VII of England and Alexandra of Denmark
Queen Victoria arranged a marriage between her eldest son, King Edward VII (then Prince Albert) of England, and Alexandra of Denmark. The two were third cousins who shared great-great-grandparents. Historians have drawn parallels between the couple and Prince Charles and Princess Diana.
King George V and Mary of Teck
King George V and Mary of Teck were second cousins. They were also not the couple originally expected to get married. Mary was due to marry Prince Albert Victor, but six weeks after their engagement, he fell ill and died. She bonded with George over the experience, and eventually it was decided the two would marry.
Queen Elizabeth II and Prince Philip
Queen Elizabeth II fell in love with Prince Philip as a young girl, but the two wouldn't marry until she was in her early 20s. The two shared a common ancestor in Queen Victoria, making them third cousins.
Prince Charles and Princess Diana
Before she was a princess, Diana was a member of the British aristocracy. She was a descendant of Lady Elizabeth Cavendish, a daughter of the 3rd Duke of Devonshire. Prince Charles descended from a son of the 3rd Duke of Devonshire. It makes them seventh cousins, once removed.
Prince Andrew and Sarah Ferguson
Sarah Ferguson is actually related to the royal family in a number of ways. Most strongly, her paternal grandmother, Marian Montagu Douglas Scott, was the first cousin of Princess Alice, Duchess of Gloucester. Princess Alice was an aunt of Queen Elizabeth II, having married Elizabeth's uncle, Prince Henry, Duke of Gloucester.
Prince William and Kate Middleton
William marrying a commoner was once a cause for concern, but the Middletons quickly found their way in royal life. Kate is actually distantly related to the royal family. Her great-great-grandmother, Frances Elizabeth Greenhow, was the 10 times great-granddaughter of Sir William Gascoigne. Sir William was married to Lady Margaret Percy, the youngest daughter of Henry Percy, Earl of Northumberland.
The Earl of Northumberland descended from King Edward III through both his parents. Additionally, Sir William and Lady Margaret are the common relatives that Prince Charles and Princess Diana share. That means that, depending on which side of the family you look at, the two are technically 14th or 15th cousins.
Prince Harry and Meghan Markle
Meghan Markle's background has been picked apart, but most people gloss over her relation to the royal family. Meghan is a 24th generation descendant of King Edward III, a medieval monarch of England who died in 1377. More simply put, Thomas Markle and the queen mother shared a common ancestor, which makes Harry and Meghan 17th cousins.
Princess Eugenie and Jack Brooksbank
Believe it or not, Princess Eugenie and Jack Brooksbank are more closely related than you'd think. Through her mother, Sarah Ferguson, she is the great-great-granddaughter of Lady Julia Coke. Lady Julia Coke is also the daughter of Jack's great-great-grandfather, Thomas William Coke. This makes them third cousins once removed, a similar relationship to what Queen Elizabeth and Prince Philip shared.
