The Roman Legend of the Origin of Soap

There is a very popular Roman legend surrounding the origin of soap. You can find it mentioned pretty much anywhere people discuss the discovery of soap and its cleansing properties. According to the legend, soap gets its name from Mount Sapo (or Sappo, in some sources), a supposed site of animal sacrifices near ancient Rome. 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 rain their clothes were much cleaner. This is supposedly how soap was named, and its cleansing properties were discovered.Unfortunately, this is most likely nothing but a myth. There are a few things that dampen the veracity of the legend. First, there is no record of any hill, mountain, or sacrificial site near Rome ever being called Mount Sapo. Second, it is not enough for fats and ashes to occasionally and surreptitiously meet in the waters of a river for them to produce soap. Third, in ancient animal sacrifices the Romans would save all the desirable meat and fat for food and burn only the bones and undesirable entrails for the gods. It is unlikely there would have been enough fat and ashes coincidentally mixing to form a significant amount of soap. The legend makes for an interesting story though!