Possible Clues:

• Monarch's self-referential plural pronoun (AL Central)
• Formal pronoun
• The Queen's I
• King's self-allusion
• Uncommon pronoun
• Victoria's one abysmally low year?
• Part of The King's Speech that might be seen in palace chambers, one's heard
• Pluralis majestatis
• Queen's pronoun
• Elizabethan pronoun?