Cartae Baronum

In the kingdom of England, a feudal barony or barony by tenure was the highest degree of feudal land tenure, namely per baroniam (Latin for "by barony") under which the land-holder owed the service of being one of the king's barons. The duties owed by and the privileges granted to feudal barons cannot now be defined exactly, but they involved the duty of providing soldiers to the royal feudal army on demand by the king, and the privilege of attendance at the king's feudal court, the precursor of parliament.

If the estate-in-land held by barony contained a significant castle as its caput baroniae and if it was especially large – consisting of more than about 20 knight's fees (each loosely equivalent to a manor) – then it was termed an "honour".

This type of barony must be distinguished from a barony, also feudal, which existed within a county palatine, such as the barony of Halton within the Palatinate of Chester.

William the Conqueror established his favoured followers as barons by enfeoffing them as tenants-in-chief with great fiefdoms to be held per baroniam, a largely standard feudal contract of tenure, common to all his barons. Such barons were not necessarily always from the greater Norman nobles, but were selected often on account of their personal abilities and usefulness. Thus for example Turstin FitzRolf, the relatively humble and obscure knight who had stepped in at the last minute to accept the position of Duke William's standard-bearer at the Battle of Hastings, was granted a barony which comprised well over twenty manors.

Lands forming a barony were often located in several different counties, not necessarily adjoining. The name of such a barony is generally deemed to be the name of the chief manor within it, known as the Caput, Latin for "head", generally assumed to have been the seat or chief residence of the first baron. So, for instance, the barony of Turstin FitzRolf became known as the barony of North Cadbury, Somerset.

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