It used to be that royals married only other royals. The ruling houses of Europe were one big intermarried clan, dubbed "the royal mob" by Queen Victoria. But after World War I, there weren't very many thrones left. Suddenly, princes seeking brides had to look beyond their own caste. But that didn't mean just anybody could be admitted to the club.
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Here's a look at some of the non-royals who have gained admittance to that select circle — or tried to crash the gate and failed.
Wallis Warfield Simpson — Britain's King Edward VIII gave up his throne to marry "the woman I love" in 1936. Mrs. Simpson was an American, but that wasn't the reason she was considered unacceptable. When she met Edward, she had already been divorced once, and was about to chuck her second husband. After his abdication, the ex-king became known as the Duke of Windsor, but his duchess was denied the title "Her Royal Highness."
Elena Lupescu — The wife of an army officer, this voluptuous redhead captured the heart of Romania's King Carol II in the 1920s. While still crown prince, Carol renounced his right to the throne and ran off to Paris with the rather grasping Elena. He later changed his mind — about the throne, not Elena — and returned to Romania, where he seized power. In 1940, he was forced to abdicate, but he managed to leave the country with a tidy little nest egg. He and Elena married and lived in exile in Portugal, where Carol died in 1953. Elena lived on for another quarter-century, presumably on the loot they removed from Romania.
Sophie Chotek — She was a countess, but that wasn't considered good enough for the Archduke Franz Ferdinand of Austria-Hungary. In 1900, he married her, but the emperor would not allow Sophie to enjoy royal status. Sophie, now known as Duchess of Hohenburg, bore her husband three children, but they were barred from the succession. Sophie accompanied her husband on that fateful visit to Sarajevo in 1914, where a Serb nationalist shot them both. Sophie died along with her husband, whose assassination sparked World War I.
Princess Diana — When "Shy Di" wed Prince Charles in 1981, the British people were enraptured by their new princess. But even though she came from an aristocratic background (her father was an earl), Diana had a hard time adjusting to royal life. She said she had an even harder time adjusting to her husband's interest in Mrs. Camilla Parker Bowles. After many acrimonious battles and tabloid scandals, Charles and Diana were finally divorced in August 1996. The princess was killed a year later in a car crash in Paris.
Crown Princess Mette-Marit — When Norway's Crown Prince Haakon fell in love with Mette-Marit Tjessem Høiby, she was a single mother with a young son from a relationship with a man convicted of drug charges. A former waitress, she had also been part of Oslo's wild "house party" circle. But having a child out of wedlock is very common in Norway, and most people were prepared to accept Mette-Marit as their future queen. Haakon's parents, King Harald V and Queen Sonja, are said to be very supportive of their daughter-in-law. Last Jan. 21, Mette-Marit gave birth to Princess Ingrid Alexandra.