Difference between Heir Presumptive and Eminence Grise

HEIR PRESUMPTIVE vs EMINENCE GRISE: NOUN

Someone who will inherit only if no better choice for an heir is born.
See heir apparent.
An heir who stands to inherit the estate, title, or office of an intestate ancestor, but whose claim can be defeated if a relative who is closer to the ancestor is born prior to the ancestor's death.
A person who expects to inherit but whose right can be defeated by the birth of a nearer relative

Alternative form of éminence grise.
(French) a person who exercises power or influence in certain areas without holding an official position

Succession, Peacock throne, Kingship, Dynastic, King, Prince consort, Princeling, Monarch, Figurehead, Prince regent, Coronation, Heir, Successor, Throne, Heir apparent

Panjandrum, Elder statesman, Protege, Intriguer, Paterfamilias, Factotum, Kremlinologist, Fuehrer, Spinmeister, Majordomo, Figurehead, Apparatchik, Amanuensis, Russophobe, Acolyte

Succession, Peacock throne, Kingship, Dynastic, King, Prince consort, Princeling, Monarch, Figurehead, Prince regent, Coronation, Heir, Successor, Throne, Heir apparent

Mythmaker, Grand inquisitor, Panjandrum, Elder statesman, Protege, Intriguer, Paterfamilias, Factotum, Kremlinologist, Fuehrer, Spinmeister, Figurehead, Amanuensis, Russophobe, Acolyte

He is the son of Eliwood, the main character of Fire Emblem: The Blazing Blade, and heir presumptive of Pherae.
Frenchman, that he is not heir presumptive to another crown, and that he has previously taken the civic oath.
Prince Albert became King George VI and the young Princess Elizabeth became heir presumptive to the throne.
Known as "The Brat" in the Heraldic Circle, the Heir-presumptive lives up to her nickname.
Roger was made lieutenant of Ireland and was declared heir presumptive to the Crown.

The talk show and comedy eminence grise had previously revealed he would be retiring next year.