primogeniture

Definition from Nolo’s Plain-English Law Dictionary

Latin for "first born." Feudal England (and many other places) practiced male primogeniture, the practice of giving the oldest son the entire estate of his parents (or nearest ancestor). If there was no male heir, the daughters inherited the property in equal shares.The intent was to preserve large properties from being broken up into small holdings, which might weaken the power of nobles.

Definition provided by Nolo’s Plain-English Law Dictionary.