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.
Crown Princess Maxima — Willem-Alexander, the heir to the Dutch throne, was once known as "the Prince of Fun." When he met Argentinean Maxima Zorreguieta, he decided to settle down. The hitch: Her father had been a member of Argentina's former junta, a repressive regime blamed for torturing and killing thousands. The solution: Maxima distanced herself from her dad, who wasn't invited to the wedding. In December 2003, the crown princess gave birth to an heir, Princess Amalia.
Mabel Wisse Smit — The Dutch government decided to accept Willem-Alexander's chosen bride, but they weren't so accommodating when it came to his younger brother's romance. Prince Johan Friso, the second of Queen Beatrix's three sons, had to renounce all rights to the throne when he married Mabel Wisse Smit, a human rights activist, in April. The couple acknowledged that, during the vetting process, they had misled the government about the extent of Wisse Smit's past relationship with a drug lord. Johan Friso gets to keep his title of prince, but his wife remains a commoner.
Princess Stephanie's Spouses — Even princesses have to kiss more than a few frogs. Monaco's "wild child" princess was traumatized by the 1982 death of her mother, former movie star Grace Kelly, in a car crash. Since then, she's made some questionable life choices. She married her former bodyguard, Daniel Ducruet, after the births of their two children, Louis and Pauline. But the marriage didn't last long; Ducruet was caught on camera cavorting with a lady who had been crowned Miss Topless Belgium. In 1998, the divorced Stephanie gave birth to a daughter, Camille Marie Kelly, whose father she has never revealed. Then the princess ran away with the circus, or rather, a circus ringmaster. Her romance with Franco Knie, a Swiss circus director and elephant trainer, didn't last, but Stephanie remained smitten by the big top. In 2003, she married Adans Lopez Peres, a Portuguese circus acrobat. The acrobat, described as a juggler and handstand expert, has not received a royal title.