A feudal baron is a vassal holding a heritable fief called a barony, comprising a specific portion of land, granted by an overlord in return for allegiance and service.
Such men, if not already noblemen,[a] were ennobled by obtaining such tenure, and had thenceforth an obligation, upon summons by writ, to attend the king's peripatetic court, the earliest form of Parliament and the House of Lords.
It was the highest form of feudal land tenure, namely per baroniam (Latin for "by barony") under which the land-holder owed the now little understood service of "being one of the king's barons".
A further duty, which involved considerable expense and travel, clearly also a privilege, was the attendance at the king's feudal court, the precursor of Parliament.
The principal benefits clearly were The estate-in-land held by barony, if containing a significant castle as its caput and if especially large, that is to say consisting of more than about 20 knight's fees (each loosely equivalent to a manor), was termed an "honour".
[3] Under the Ancien Régime until the abolition of the feudal system in 1789, a French baron was any noble in possession of fief called a barony.