The fairy-tale wedding—as a consumable good, not a fictional happy ending—arrived in the United States in the 1950s, says Stephanie Coontz, a professor of marriage and family history at Evergreen State College. When World War II ended, marriage rates skyrocketed. Women, employed during the war while the men were away, left the workplace in droves and got married. In 1950, the average age of marriage for women was 20. “If you waited four or five years after that, you’d be labeled a spinster,” Coontz said. In the midst of that pressure, the wedding industry identified an enormous opportunity, using ads to convince women that their wedding would be the biggest day of their lives. At the same time, Disney debuted its rendition of the world’s most famous fictional princess: When it came out in 1950, Cinderella—which ends, of course, in a gilded royal wedding—was, by one count, the highest-grossing film of the year. And so began what Coontz calls “the relentless pursuit of the princess.”

There was something special about Cinderella. In the sweet girl next door who talks to birds and sleeps in the kitchen, Coontz told me, women saw themselves. “This idea that someone who can support you at that level of opulence chooses you, instead of a blue blood … that is a very attractive fantasy,” Coontz says. Particularly after Grace Kelly—another “commoner” (who, yes, happened to be a wildly famous actress)—married Prince Rainier of Monaco in 1956, the fairy-tale wedding suddenly felt, well, if not within reach, then at least something worth fantasizing about. The most recent royal marriages, according to Coontz, have been so popular because they play out the same storyline: Rich, royal dude swoops in to save a regular girl from a lifetime of oppressive normality. (Both Middleton and Markle were considered “commoners” at the time of their engagements, though genealogists have since claimed distant royal ties.) “In the past, kings and princes couldn’t marry commoners, so there was no point in fantasizing about it much,” Coontz said. “Now we’ve seen the idea of a ‘love match’ become a reality.”