@helenstwin's list of Historical Romance Tropes

Compiled with her mother's assistance for Bellwether Friends Episode 41 (https://bellwetherfriends.wordpress.com/2016/07/21/episode-41-we-love-historical-romance/)
  1. Accidental carriage rides (bonus: kidnapped the wrong person)
  2. One of them is pretending to be someone they are not
  3. The family sets up a terrible marriage and the hero or heroine marries someone else in a panic
  4. The hero or heroine has to marry because of a will (or a grandmother who threatens to cut them off)
  5. The heroine accidentally gets compromised
  6. They used to be married, and are getting back together
  7. They've known each other all their lives (bonus if the heroine has actually been in love with the rogue younger brother but married the responsible, stuffy older brother)
  8. They are thrown together because one of them is (decorating the other's house, chaperoning the other's little sister, teaching the other how to get along in society). They start out hating each other.
  9. Professional woman (bonus if lady journalist)
  10. Rogues! Who change! For the right woman!
  11. Dukes who are somehow really hot!
    So. Many. Dukes.
  12. The hero's older brother dies, so now he has to marry and stop his roguing because he's the heir
  13. He wins/loses a game of cards
  14. He needs a mother for his children
    Who doesn't, am I right?
  15. She's an old maid!
  16. She's a nanny!
  17. She's a orphan and an heiress!
  18. One of them has a terrible secret that will destroy their love
    Of course