Aquisgran Empire is divided in seven duchys, eight on paper: Galvania, Silver, Solstice, Bulwark, Ustan, Desta and Estragon. The eighth duchy is in theory Umbria, as they haven't accepted their independance, but they cannot rule it and they know it.
The empire ruler is the Emperor, who must hear the advice of the dukes, needing the support of at least five of them to take an important decision. Their law is based on the laws of the Santuarian Empire but modified for centuries by the duke council. When an emperor dies the dukes make an election between them to chose a new emperor, being the dukes of the families Eryn, Unithgol and Mellit the most common emperors because of their influence. Because its considered an important decision, five votes are required.