Mihály Zichy (1827–1906) was a Hungarian born artist who is best known by the majority for his contributions towards the Romantic movement, though best known to eroticaphiles for the many erotic pencil drawings he drew after settling in France after 1871.
It is unknown how many of these erotic drawings he produced altogether or what motivated him to produce them. Most are very beautiful and have a brilliant energy.
These drawings all show various sexual depictions including classic bedroom scenes between couples in many positions, acts of fellatio and cunnilingus, mutual masturbation between same sex couples and some particularly emotive and powerful drawings of sex between centaurs.(Text source)
Wikipedia briefly tells us about erotica
On tumblr, a stunning collection of erotic images from over the centuries: Old erotic art