Emperor

The Emperor is the ruling monarch of the Third Imperium and is the focal point of every oath of fealty and service within the Imperial civil service, military, and nobility. The actual appellation Emperor is a genderless title in the Imperium, although some female oocupants of the Iridium Throne have preferred the the old Terran term Empress. The Emperor wields the Imperial Mandate over all Imperial territories, however, the Emperor is not a high noble since they are the source of nobility and authority and the rest of the nobility are his representatives and viceroys.
The Emperors usually use only their given name (Emperor Harold, Empress Harriet) in most situations. Formally, they are introduced as "Their Imperial Majesty, Empress Harriet Smith Blogs", and are addressed as "Your Imperial Majesty".