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... and a small piece of advice for you - don't try being clever - you are not clever enough !
You seem blissfully unaware that until the Births, Marriage and Deaths Act of 1836 there was absolutely no need whatsoever to register a marriage in civil law.
If two people considered themselves married - they were. (Anglicans could always register their marriage in Church registers, but there was an increasing number of dissenters - Quakers, Catholics etc - who did not attend Anglican church. Therefor numerous marriages were going unrecorded at all).
Its clear (from his will) and the fact that he asked specifically to be buried with Maria Fitzherbert's photo, that he considered her to be his lawful wife. (He had only married Caroline so Parliament would wipe out his debts - and dumped her as soon as he could). Parliament was also against the Fitzherbert marriage due to her Catholicism (but many Kings converted to Catholicism - eg Charles II, on his deathbed ! - or practised it illegally). The Pope confirmed the marriage was lawful and valid.
Even the Duke of Wellington - George's executor (in his memoirs) accepts they were man and wife.
George's successor, William IV, acknowledged the part that Maria played in George's life in his very first action as King.