„According to Roman legend, soap was named after Mount Sapo, an ancient site of animal sacrifices. After an animal sacrifice, rain would wash animal fat and ash, that collected under the ceremonial altars, down to the banks of the Tiber River.

Women washing clothes in the river noticed that if they washed their clothes in certain parts of the river after a heavy rainfall their clothes were much cleaner. Thus the emergence of the first soap – or at least the first use of soap.

The word "sapo" first appears in a book written in Latin titled "Natural History" by Pliny the Elder an academic from Pompeii. 

The earliest known written soap recipe was written on clay tablets and is credited to the ancient Babylonians. A soap-like material found in clay cylinders during the excavation of Babylon a city in ancient Mesopotamia, between the Tigris and Euphrates rivers, is evidence that soapmaking was known as early as 2800 B.C.“