What "genre" of printed material _did_ exist before 1500? For that matter, what year did the word "genre" come to life as a way of classifying literature? It can't have been before there were printing presses in copious numbers.
Meanwhile: Sex is fun because of our wiring, and porn is old. What's the point of denying these two plain facts, anyway?
Pornography (from Encyclopedia Britannica online):
The representation of erotic behaviour in books, pictures, statues, motion pictures, etc., that is intended to cause sexual excitement. The word pornography, derived from the Greek porni ("prostitute") and graphein ("to write"), was originally defined as any work of art or literature depicting the life of prostitutes.
Little is known of the origins and earliest forms of pornography because it was customarily not thought worthy of transmission or preservation. One of the first clear historical evidences of pornography in Western culture can be found in the salacious songs performed in ancient Greece at festivals honouring the god Dionysius. Indisputable evidence of graphic pornography in Roman culture is found at Pompeii, where erotic paintings dating from the 1st century AD cover walls sacred to bacchanalian orgies. A classic of written pornography is the Roman poet Ovid's Ars amatoria (Art of Love), a treatise on the art of seduction, intrigue, and sensual arousal.
During the European Middle Ages pornography was widespread but held in low repute, finding expression mostly in riddles, common jokes, doggerel, and satirical verses. A notable exception is the Decameron of Giovanni Boccaccio, some of whose 100 stories are licentious in nature. A principal theme of medieval pornography was the sexual license of monks and other clerics, along with their attendant displays of hypocrisy.