The Regency era lasted about nine years. From 1811 to 1820. And yet it has generated more romance novels than any other period in Western history.
I think the reason is structural. The Regency comes preloaded with the best machinery for generating romantic tension any period has ever produced. The Season. The marriage market. The scandal system. A single dance could ruin a woman's reputation if she held the wrong man's gaze for two bars too long. You don't have to invent the stakes. The calendar does it for you.
Eloisa James is also Mary Bly, a Shakespeare professor at Fordham University. She teaches early modern literature during the day and writes Regency romance at night. Her Desperate Duchesses series and her Wilde series are built on period knowledge that goes past costume and into how people actually thought, what they found funny, what worried them when they couldn't sleep. The details don't sit on the surface. They're load-bearing.
There's a difference between a historical romance and a romance that happens to be set in history. In the first, the period is the engine. The constraints of the era create the tension, shape the characters' choices, make certain kinds of love possible and other kinds dangerous. In the second, the period is wallpaper. You could move the plot to a modern coffee shop and nothing would break.
The wallflower trope persists because every reader has felt invisible at a party. That specific feeling of standing at the edge of a room, watching everyone else get chosen, is so universal it barely needs context. Historical romance just gives it the cruelest possible staging: a ballroom where your social worth is determined by whether someone asks you to dance.
James once said that "romance novels are the only genre in which the reader's experience of pleasure is built into the narrative structure." I keep coming back to this. Romance is contractually obligated to deliver emotional satisfaction, and the reader knows this going in, and somehow the knowing doesn't ruin it. The tension comes not from whether the couple will end up together but from how and what it will cost them to get there.
Courtney Milan has a JD from Michigan Law School. Her legal training shows up everywhere in her Brothers Sinister series, but not in courtroom scenes. She writes social constraint as a system. Her heroines include a mixed-race woman navigating Victorian high society, a woman managing a chronic illness in an era that would have institutionalized her for it. Milan builds plots the way a lawyer builds a case: here is the rule, here is why the rule is unjust, here is the person who will break it.
The rake-reformed trope is historical romance's signature character arc. I think it endures because it's really a story about whether people can change. Whether they can do the slow, unglamorous work of becoming someone different. The rake doesn't just stop gambling. He loses friends. He sits with boredom. He finds out the person he was had some things going for him that the person he's becoming does not.
The marriage of convenience was historically far more common than the love match. Marriage was an economic arrangement. Love, when it appeared, was a pleasant accident. Historical romance inverts this: two people enter a practical arrangement and then, against their own wishes, fall in love anyway. The trope works because it starts from emotional safety. Neither party expects anything. And that safety is what lets them risk being honest.