No one knows where soap making began. Clay tablets dating back to 2500 BC suggest that soap was first used for styling hair, as well as to aid in healing wounds. Ancient Greeks were said to use a combination of lye and ashes to clean their pots and the statues of their gods.
Cleopatra used milk, honey and essential oils in her bathing
rituals. She used sand as a cleaning agent, scrubbing off skin as well
as dirt. In ancient Rome, oils were used that were then scraped off the
body with a strigil, taking some of the dirt with the oil.
The Gauls and the Romans combined goat's tallow and the ashes of the
beech tree to create their soaps. Roman legend has it that soap got
it's name from Mount Sapo, where animals were sacrificed. Rain washed
the ashes and animal fats down the mountain into the clay soil along
the Tiber River. Women washing clothes there found that the clothes
came clean more easily using this mixture.
The first of the Roman baths using water from their aqueducts was built about 312 BC and bathing became quite popular. By the second century AD, soap was recommended for both medicinal and cleaning reasons. During excavations of Pompeii, an entire soap making factory was revealed, complete with bars of soap. After the fall of Rome, bathing and using soap declined, possibly aiding the spread of plagues during the Dark Ages. Japan and Iceland continued bathing throughout this time period.
In 1399, King Henry IV of England instituted the Order of the Bath among his knights. To join this order the knight had to venture into a tub filled with water at least once during his knighthood. Queen Elizabeth bathed every three months, and was considered a sophisticated lady.
Marseilles, France was reknown for its soap. The plentiful olive trees supplied the olive oil, and vegetable soda was also abundant. In the early days of the United States, pilgrims and pioneers made their own soap once a year on soap making day. This lye soap was fine for washing clothes, but was hard on the skin and not pleasant for bathing.
Palmolive soap, made from palm and olive oils, was in use before 1917. Ivory soap came about when a worker accidentally left the soap mixer running while he went to lunch; incorporating more air into the mixture and creating a soap that floats. Regardless of how soap use began, we can say with confidence that it's use is here to stay.