His/Her Serene Highness (
abbreviation:
HSH) is a
style used today by the
reigning families of
Liechtenstein and
Monaco. Until 1918 it was also associated with the princely titles of members of some German ruling and
mediatised dynasties, and with a few
princely but non-ruling families. It was also the form of address used for
cadet members of the dynasties of France, Italy, Russia and
Ernestine Saxony under their
monarchies. Additionally, the treatment was granted for some, but not all, princely yet non-reigning families of Bohemia, Hungary, Italy, Poland, Romania and Russia by emperors or popes.