Many legends refer to the invention of soap.  Soap suds may have been seen in prehistoric times by early man cooking meats over a fire.  After a rainstorm they might have noticed there was a strange soapy foam around the remains of the fire after the meat fats (fatty acids) mixed with the potash / wood ash (alkali) from the fire.

Ancient Roman legend claims that soap was first discovered by women washing clothes along the Tiber River at the bottom of Sapo Hill (this may be where the word "saponification", the chemical name for the soap making reaction, came from).  Women apparently noticed their clothes were easier to wash when using the foaming soapy water.  This occurred after rain washed the burnt ashes and animal fat from the sacrificial fires of the temples on top of Sapo Hill down to the river.

Archaeological evidence of soap was apparently found in Babylonian clay containers dated 2800 B.C. with inscriptions stating that the soap was made from fats boiled with ashes.  This was probably used to wash wool used in textile manufacture.

It is said that the first definite proof of soap making is recorded by Pliny, the Ancient Roman historian, who described soap being made from goat's fat and wood ashes.  The ruins at Pompeii are also believed to have revealed a soap factory complete with finished bars.

Soap making dramatically progressed around the 8th Century when Italy, Spain and France became the centers of soap manufacturing due to their supply of raw materials such as olive oil from their olive groves.  Soap making Guilds guarded their trade secrets closely.

The English began making soap during the 12th century which was mostly made from rendered animal fat (tallow), but when Britain started to import vegetable oils such as olive, palm and coconut from abroad, production of soap started in and around the ports of Bristol and London.

In 1791 a French chemist, Nicholas Leblanc, patented a process for making sodium carbonate from common salt, and 20 years later another French chemist, Michel Eugene Chevreul, discovered the chemical nature of fats, glycerine and fatty acids, and the science of modern soap making was born.  These discoveries, together with the development of power to operate factories, were a major step toward large-scale commercial soap making.

However in the 19th century, soap was heavily taxed as a luxury item in England and other countries making it only affordable by the rich.  When the high tax was removed in 1852, soap became available to ordinary people, and with the introduction of plumbing and hot a cold running water soap was brought into homes and cleanliness standards improved.

Most of today's commercial soap making processes are far removed from the 19th Century commercial soap making methods.  Many commercial soap bars, liquid soap, shower gels and bubble baths/creams are just detergents, containing harsh chemicals and cheap synthetic fragrances which can cause dry, irritated skin and split nails.  They also lack the main ingredient that makes soap so good for your skin - the naturally occurring glycerine.  Glycerine is often removed from mass-produced soap bars and added to creams and lotions so that the consumer purchases a whole range of products instead of one good one.