Soap
Is there any invention as ancient and as fundamental as soap? Traced to Babylonian civilisation around 2,800 bc (handy for scrubbing down after all that gardening), it almost certainly goes back millennia further than that. It is mentioned in the Book of Jeremiah and by 1550 bc the Egyptians were marketing it as a medicinal aid for sores and other skin ailments. There was a soap factory buried in Pompeii — although the product is believed to have been used more for washing clothes because visitors to Roman bath houses preferred to scrub themselves with olive oil.