#OTD in 1748.
The first instalment of Memoirs of a Woman of Pleasure, also known as Fanny Hill, is published anonymously by John Cleland to raise money to free himself from the London debtors' prison. It is considered by some to be the first modern erotic novel.
https://en.wikipedia.org/wiki/Fanny_Hill
Memoirs of Fanny Hill at PG:
https://gutenberg.org/ebooks/25305