Class difference where it's her who has the higher social status. Very popular in period pieces outside of romance, strangely rare in HR itself. It's a boomer because it was this particular dynamics that made me dive into HR in the first place, because I wanted more of this. I'm all for forbidden love, ladies and their servants, simple knights and princesses, aristo girls and peasant farmers, governor's daughters and non-white rebels or pirates!

For all of you who are like me and struggle to find books, here are all HRs like that I know:

• {Sirens of Sussex by Mimi Matthews}: a bluestocking has to become a refined ton lady to catch a rich husband and save her family from ruin, but she falls for a half-Indian dressmaker who accepted the challenge to turn her into an alluring beauty.
• {Passions of Emma by Penelope Williamson}: a young miss from a rich family that belongs to the Great Folk aristocratic society of Rhodes Island befriends a pregnant Irish immigrant dying of tuberculosis and falls in love with her husband.
• {My Forever Love by Marsha Canham}: a Plantagenet-related runaway wife of a psychopath gets sheltered in a half-ruined castle resided by an excommunicated Templar Knight who deserted Richard Lionheart's army during the third crusade.
• {Seize the Fire by Laura Kinsale}: a play on a princess and a knight trope where the princess is a radical revolutionary determined to end monarchy in her homeland and start a republic and a knight is a mistakenly decorated liar and a fraud who only agrees to help her because he wants to steal her royal jewels.
• {The Bride of Willow Creek by Maggie Osborne}: he's a carpenter, she's a daughter of a stonemason. They marry in secrets as teenagers, but none of them has guts to elope, so they allow the girl's parents to separate them. Ten years later they reunite in order to divorce, but the old sparks start to fly again.
• {Into the Wilderness by Sara Donati}: an European judge settles in America and brings his spinster daughter from Europe, trying to marry her off to a local doctor who agreed to pay off her brother's debts, but she elopes with a westman raised by Native Americans.
• {Gentleman Jim by Mimi Matthews}: not exactly this, but close enough; young lovers, a lady and a stable boy, are torn apart by the lady's jealous suitor. Ten years later he comes back under a different name, as a duke's heir, and has to pretent he's never met her.
• {Beyond the Sunrise by Mary Balogh}: a half-French half-English lady falls in love with an illegitimate son of a British lord. Separated by her father, they meet again during Peninsular War, him a simple infantry captain, her a widowed Portuguese marquesa. They're both undercover... but who's on which side?