A principle or set of principles lay down by authority as incontrovertibly true
In a feudal system, a vassal, akin to a serf in most contexts, in general worked land on a lord's fiefdom in exchange for some of the produce from the land and some military protection.
Answer:
You will find everything you need, here!
https://www.dol.gov/general/aboutdol/history/dolchp06
Explanation:
