University of Wolverhampton carried out a research project to discover the history of jokes.
This Dave Historical Humor Study defined a joke as having a clear set-up and punch-line structure. They were then able to plot jokes as far back as 1900 B.C.
The oldest known one is a Sumerian proverb. Most of the noted jokes deal with crude material. For example, one from 1600 B.C. Asks what you do to entertain a bored Pharaoh.
The answer: You sail a boatload of women dressed in fishnets down the Nile and tell him to go catch a fish.
The oldest known joke in the UK dates back to the 10th century AD and appears in the Exeter Codex.
Following in its crude predecessor's footsteps, it asks "what hangs at a man's thigh and wants to poke the hole that it's often poked before?" The answer: A key.