And probably the original use of the saying “you’re not worth your salt.”
Salt and vinegar, some money, plus room and board, lots of hard work, free health care, occasional spoils, and (after the fall of the so-called Roman Republic) those who served out their enlistments got land. The book “The Roman Empire and the Indian Ocean” discusses the Roman tax structure (obviously including import and export duties) and based on the documents which survive, a handful of the provinces more than paid for everything, while most provinces cost more to garrison and such than was generated in tax revenues.
https://www.pen-and-sword.co.uk/The-Roman-Empire-and-the-Indian-Ocean-ePub/p/10061
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