Roman Monarchy

The Rhomanian monarchy is theoretically the supreme executive power of the Roman Empire. Technically, the Emperor exists not as merely a Roman Emperor (βασιλεύς Ῥωμαίων, basileus Rhomaíōn), but as "Emperor of the Romans and the Bulgarians" (basileus Rhomaíōn kai Boulgaroi), though, in practise, the latter title is generally abandoned.

[http://isaacsempire.wikia.com/wiki/Category:List_of_Emperors List of Roman Emperors in the IE world. ]