The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BC in Ancient Babylon. In the reign of Nabonidus (556–539 BCE) a recipe for soap consisted of uhulu [ashes], cypress [oil] and sesame [seed oil] “for washing the stones for the servant girls”. A formula for soap consisting of water, alkali, and cassia oil was written on a Babylonian clay tablet around 2200 BC.
The Ebers papyrus (Egypt, 1550 BC) indicates that ancient Egyptians bathed regularly and combined animal and vegetable oils with alkaline salts to create a soap-like substance. Egyptian documents mention that a soap-like substance was used in the preparation of wool for weaving (need references).
The word sapo, Latin for soap, first appears in Pliny the Elder’s Historia Naturalis, which discusses the manufacture of soap fromtallow and ashes, but the only use he mentions for it is as a pomade for hair; he mentions rather disapprovingly that the men of the Gauls and Germans were more likely to use it than their female counterparts. Aretaeus of Cappadocia, writing in the first century AD, observes among “Celts, which are men called Gauls, those alkaline substances that are made into balls, calledsoap”.
A popular belief encountered in some places claims that soap takes its name from a supposed Mount Sapo, where animal sacrifices were supposed to take place—tallow from these sacrifices would then have mixed with ashes from fires associated with these sacrifices and with water to produce soap. But there is no evidence of a Mount Sapo within the Roman world and no evidence for the apocryphal story.