#OTD in 1798.
Elizabeth Inchbald's Lovers' Vows (adapted from Kotzebue's Das Kind der Liebe – 1780; literally "Love Child," or "Natural Son," as it is often translated) is first performed at the Theatre Royal, Drury Lane, London.
It was likewise successful as a print publication, though it also aroused controversy about its "levelling" politics and moral ambiguity.
https://en.wikipedia.org/wiki/Lovers%27_Vows
Lovers' Vows at PG:
https://www.gutenberg.org/ebooks/4554