porphyrogeniture การใช้

Henry argued that, unlike Robert, he had been born to a reigning king and queen, thereby giving him a claim under the right of porphyrogeniture.
In some cases, distinctions were even made based on whether the claimant was born to a monarch who reigned at the time of birth ( porphyrogeniture ).
In late 11th century England and Normandy, the theory of porphyrogeniture was used by Henry I of England to justify why he, and not his older brother Robert Curthose, should inherit the throne after the death of their brother William Rufus.