#i'm not saying that henry/arundel viewed the beauforts as a threat to the succession of the prince

[une-sanz-pluis]

Hi, what exactly did the royal charter excluding the Beaufort family from the throne say?

Hi! So in February 1407, John Beaufort, Earl of Somerset requested that the act legitimatising him and his siblings be confirmed by Letters Patent, which he duly received. At the same time, the royal charter that legitimised the Beauforts was modified by the insertion of the words excepta dignitate regali ("except to royal dignity"). I believe the royal charter is in the Parliament Rolls of Medieval England which I don't have access to but a 19th century historian published a transcription:

Be it remembered, that on Tuesday the fifteenth day of Parliament, the Chancellor, by the King's command, declared how our Holy Father the Pope had, in reverence of the most excellent person of the King, and of his honorable uncle the Duke of Guyenne and of Lancaster, and of his blood, enabled and legitimatized Sir John de Beauford, his brothers and his sister, and that therefore our Lord the King as entire Sovereign of his Realm of England, for the honour of his blood, wills, and hath of his full royal power enabled and of his own proper authority made the said John, his said brothers and sister, muliers, and also pronounced and published the ability and legitimatization according to the form of the King's charter thereof made. The which charter was read in full Parliament and delivered to the said Duke, father of the said John, and his said brothers and sister, the tenor of which charter ensueth. Richard by the grace of God, King of England and France, and Lord of Ireland, to our most dear cousins the noble men, John the Knight, Henry the Clerk, Thomas 'Domicello,' and to our beloved the noble woman Joan Beaufond 'Domicelle,' the most dear relatives of our uncle the noble John Duke of Lancaster, born our lieges, greeting, and the favour of our royal majesty. Whilst internally considering how incessantly and with what honours we are graced by the very useful and sincere affection of our aforesaid uncle, and by the wisdom of his counsel, we think it proper and fit that, for the sake of his merits, and in contemplation of his favors, we should enrich you (who are endowed by nature with great probity and honesty of life and behaviour, and are begotten of royal blood, and by the divine gift are adorned with many virtues,) with the strength of our royal prerogative of favour and grace. Hence it is, that, yielding to the entreaties of our said uncle your father, we do, in the fullness of our royal power and by the assent of Parliament, by the tenor of these presents empower you, who as it is asserted suffer from the want of birthright, (notwithstanding such defect, which, and the qualities thereof, we take to be in these presents sufficiently expressed) to be raised, promoted, elected, assume, and be admitted to all honours, dignities, [except to the royal dignity] pre-eminencies, estates, degrees and offices public and private whatsoever, as well perpetual as temporal, and feodal and noble, by whatsoever names they may be designated, whether they be Duchies, Principalities, Earldoms, Baronies or other fees, and whether they depend or are holden of us mediately or immediately, and to receive, retain, bear, and exercise the same as freely and lawfully as if ye were born in lawful matrimony, and you and every of you do restore and legitimatize : any statutes or customs of our realm of England to the contraiy thereof made or observed (which we consider to be herein fully expressed) in anywise notwithstanding. (Source: Samuel Bentley, Excerpta Historica, Or Illustrations of English History (1831))

Wars of the Roses historians generally credit this addition to Henry IV, historians of Henry IV to Thomas Arundel, Archbishop of Canterbury who was no Beaufort fan and in a powerful position during this time due to Henry IV's illness.