(I hope this is the right place to ask this)
I was watching the British TV show 'Victoria' and in one scene Ernest August, King of Hanover and uncle of Queen Victoria is announced as "HRH...". Shouldn't it be HM? Or was the Hanoverian king somehow inferior to the British queen? Or are foreign royals always styled as HRH?
Edit: please excuse the profanity of my question.
This would appear to be a slip up by the screenwriters, rather than an accurate portrayal of royal etiquette in the early Victorian period.
There is plenty of evidence that the title "His Majesty the King of Hanover" was in use in official circles in this period - see this Google Books Search – whereas the term "His Royal Highness the King of Hanover" does not appear at all in the same sample period, 1838-1844.
One possible reason for the confusion does emerge from these two searches, in that Ernest Augustus in fact held both titles. That is, he was not only His Majesty the King of Hanover - which was the most senior of his titles, and thus the one by which he was generally known – but simultaneously HRH the Duke of Cumberland. I am no expert on royal protocol, but it seems possible that on occasions when he was present in the latter capacity, rather than the former, the HRH title would have been the correct one to use - but in the form HRH the Duke of Cumberland, not HRH the King of Hanover.