The political faction that Sigmar Heldenhammer is the patron deity of is based on what real-world empire?
Sigmar Sigmar Heldenhammer is a fictional deity in the "Warhammer Fantasy" setting. He is the patron deity of The Empire. Before he became a god, Sigmar was a man, albeit an exceptional, perhaps even superhuman one. The young chieftain of the Unberogens who lived 2,500 years before the present day of the Warhammer universe, he united the barbarian human tribes into what would become the mightiest human nation – the Empire. His sign is a twin-tailed comet or a war hammer.
Consortium imperii Consortium imperii is a Latin term dating from the Roman Dominate, denoting the sharing of imperial authority between two or more emperors, each hence designated as "consors imperii", i.e. "partner in (exercising) "imperium"", either as formal equals or in subordination, in which case the junior was often the senior's designated heir—not necessarily the natural one—and successor. In theory, this arrangement served to share the burden of government and ensure smooth succession, as rivalry at these moments was a major threat to the stability of the Empire; however, in practice the net result was often more civil war.