The earliest example of a bar joke is Sumerian, on a tablet dating from the early Old
Babylonian Empire (c. 1894-1800 BC), and it features a dog: "A dog, having walked into an inn, did not see anything, (and so he said): 'Shall I open this (door)?'." The humor of it is probably related to the Sumer
way of life and has been lost, but
the words remain.