Question

Difference between serene highness and royal highness

Answer 1

The style His/Her Royal Highness ranks below His/Her Imperial Highness (referring to an Imperial House which is above a Royal House) but above His/Her Highness & His/Her Serene Highness (referring to Princely or Ducal Houses which are below that of a Royal House).

Order by abbreviation...

HIH
HRH
HGDH
HSH
HH


"MII"

Answer 2

Explanation:

They're to all intents and purposes simply a different way of expressing the word “Highness”. The royal families of Monaco and Liechtenstein use Serene Highness for all their royal family members; other royal families use Royal Highness for all royal family members who are not the king or queen.