Throughout history, the growth of a population has been predicated on the availability of food. Most of the largest cities in the world are located on a river since water was important for agriculture. Even so, there were always seasons when agriculture would not be possible. As villages, towns and cities developed, the produce from the summer needed to be preserved during winters.
One of the best means of preserving food, especially meat and fish was with salt. Salt would dehydrate and preserve the meat for longer periods of time. This led to increasing demand for salt and made the mineral quite valuable.
Salt used to be mined at this time rather than being derived from the sea. This meant a lot of labour needed to be expended for extracting salt. Salt was known as ‘White Gold’.
Roman soldiers were therefore partly paid in Salt. Sal is the word for Salt in Latin. The part of the pay that soldiers received in salt came to be known as salarium, Latin for ‘salt money’.
To sit above or below salt at a feast, identified precedence. To not be worth one’s salt was a great insult.
We derive the word Salary from salarium. French and Spanish also derive their words for salary from the same source; salaire in French and salario in Spanish.