Princess Caroline of Hanover is referred to as an HRH and HSH. What is the difference?

[thanks to Brian]

His/Her Serene Highness (HSH) is used in dynasties who have a ruling prince. Caroline was born a Princess of Monaco, the reigning princely house being Grimaldi. Hence her title was “Her Serene Highness”. This style is also seen in the princely family of Liechtenstein.

Since her marriage to Prince Ernst August of Hanover in 1999, Caroline has been “Her Royal Highness”. This is only a courtesy in European royal courts however, since Germany abolished any royal and noble titles in 1918. Legally the titles are considered only as surnames.

His/Her Royal Highness (HRH) is a style used by children of kings, queens, grand dukes, and dukes (non-royal dukes are “Your Grace”). HRH ranks above a Serene Highness in order of precedence.

I can definitely see why this particular issue may be confusing to people. The question was, “Why does the late Queen Mum’s position not count in the order of Queens? There has been the Virgin Queen (Elizabeth I), and now Queen Elizabeth II. They’re not counting the Queen’s mother?”

The “numbering” of a monarch only applies to those who are regnant (reigning). Elizabeth II is regnant – in other words, she is Queen through her birthright, like Elizabeth I. The Queen Mum, however, was only Queen Elizabeth because she was married to a king. A consort only.

Thanks to Joyce for that question!