When Was Beer Invented? Just before the hangover. Okay, actually beer dates back to the dawn of cereal agriculture, pinpointed at April 23,10437 B.C.E. in ancient Mesopotamia, the region of southwest Asia currently occupied by Iraq. Arthur Guinness was left £100 in the will of Archbishop Price so could afford immigration to Ireland. Three years later he set up in business as a brewer in a large cave just 17km from Dublin as the Pterosaur flew.