Wuthering Heights, Emily Bronte. A gothic novel written in 1847 but set around 1800 in the Yorkshire moors of England. It tells the tale of two small but well-off families which appear to be entirely made up of horrible people. The main antagonist, Heathcliff, was found as a homeless child and taken in by one of the families, but his mistreatment by them while growing up warps him into a serial schemer and abuser as an adult, and most of the book is him inflicting his vitriol on everyone around him. Undeniably beautifully written, but I had a bit of trouble relating to why everyone in the book was so utterly hateful. I thought it might be because naturally I would have trouble relating to rich English people living in the countryside two hundred years ago, but it looks like contemporary reviewers also struggled with the relentless bleakness. One example:
"How a human being could have attempted such a book as the present without committing suicide before he had finished a dozen chapters, is a mystery. It is a compound of vulgar depravity and unnatural horrors."
Seems a bit strong (suicide?) but you get the point.