The Man Who Laughs (1928) by Paul Leni.
One of the most iconic and influential silent films of all time (along with Metropolis, Nosferatu, and The Cabinet of Dr. Caligari).
A magnificent film and one of my favorites.
Highly recommend checking it out.
And, yes, Conrad Veidt's interpretation (and Jack Pierce's make-up) inspired The Joker.
L'Homme qui rit, The Man Who Laughs: A Romance of English History (or By Order of the King/On the King's Command) by Victor Hugo.
A poignant, profound and tragic story.
One of my top ten.