E. Employment
After 146 BCE, the fall of Carthage by the Romans, they realized the loophole with mercenaries and introduced “Employment” and offered weekly Salaries to the recruits(permanent army).
Back then, salt was produced only in limited quantity only in the northern regions of what is modern-day Belgium today. Salt had a high demand and low production. Romans realized that if they could pay people to buy regular salt, that would be a great motivation for people to get rid of their mercenary mindset and join the mainstream army.
The word “Salary” came from salt. After the Roman army became an organized unit with employed forces, Romans brought the former mercenaries and their children to Rome and educated them in Roman culture, lifestyle, and Latin. This further had a great influence on creating the Roman Empire brand.
Rome then extended the employment concept to the slaves too. Now slaves were employed in mines, schools, and construction. Collars and leashes were replaced with Salary. This made the empire look civilized before the world and other free tribes were called the barbarians.
Food, education, housing, hospitals, and several other facilities were added with employment, besides something called retirement, whose age was 60. So slaves who were employed would be declared free citizens when they became 60 and would retire with money to live a life after retirement freely. (Though during Roman times, not many lived past that age anyways).