Proximity of blood, or proximity by degree of kinship, is one of the ways to determine hereditary succession based on genealogy. In effect, the application of this rule is a refusal to recognize the right of representation, a component of primogeniture. [1]
In some feudal entities, proximity of blood was a generally accepted principle. For example, according to the "ancient custom" (French : ancienne coutume) in the Duchy of Burgundy, a grandson could not take precedence over a son or daughter, and it was not even clear whether the ruler's grandson could claim precedence over the ruler's brother. [2]
Proximity of blood and primogeniture were at loggerheads in numerous medieval succession disputes.