No one really knows who discovered soap
There are a lot of legends about the soap discovery. There is a Roman legend, that says that soap was discovered in Mount Sapo. It is an ancient site of animal sacrifices. Animal sacrifice is an act of killing an animal as an offering to God. After an animal sacrifice rain washed animal fat and ash from the ceremonial altars to the river. Women who washed clothes in the river noticed thatin certain parts of the river after a heavy rain their clothes were much cleaner. That was the first use of soap. Soapmaking was known in 2800 B.C. Babylonians and Israelites boiled fats with ashesto make a gel that they used on hair. Greeks used soap for both medicinal and cleansing purposes. Romans had a habit of bathing with soap and spread the habit all over Europe. When Rome fell in 467 A.D., the bathing habit fell too. Many diseases appeared in poor living conditions.
Among the diseases were many plagues of the Middle Ages.
In the seventh century soap-making appeared in Spain and Italy. The Spanish and Italians made soap with goat fat and Beech tree ashes. The French started using olive oil to make soap. Eventually, specialized soaps with fragrances for bathing, shaving, shampooing, and laundry began to appear. The fragrancies had a pleasant and sweet smell. But some fragrancies were not safe. King Louis XIV of France guillotined three soap-makers for making a bar that irritated his very sensitive Royal skin.
The English began making soap in the 12th century. Wealthy ladies of the Tudor period (1485-1603) used a scented and fragrant toilet soapfor their daily washing. This soap was made with olive oil and it was very expensive. Later people could read a household instruction with recipes for soap for personal hygiene. During the reign of Elizabeth I, the English used soap more than any other European country. They followed the fashion set byQueen Bess. She set the fashion to takea bath every four weeks.
In some countries the use of soap was restricted. It was a subject of crippling taxation. Only in1853 the tax on soap was abolished.
In 18th century bathing came into fashion.In19th century, soap making was one of the fastest growing industries in the U.S. Rural Americans made homemade soap with ashes from their fires which they saved for months. When they had enough fat left over from butchering hogs they made soap.
At war the need for soap increased and commercial soapcame into existence.