God-Emperor

Once the mortal ruler of the Imperium, he ascended to divinity in A.I. 120 and ruled over the Imperium the for next three centuries. Most scholars characterize the God-Emperor's rule as an enlightened and benevolent autocracy, where the ruler he used his divine powers to ensure that Justice and Order reigned throughout the empire (it should be noted that most of these sources were imperial scholars).

The God-Emperor ruled the Imperium together with the Archmistress of Magic, he focused mostly on the running of the empire while the other Living God focused on the advancement of Magic and Science and how to harness them for the betterment of their subjects.

Although the Imperium was ruled by the Living Gods, their worship was not mandatory within the Imperium. Most scholars theorized that the freedom to worship any deity was part of the contract the Living Gods struck with the Gods to allow their ascension to divinity.

When the demon hordes invaded the Imperial City in A.I. 400 the God-Emperor faced the Demon Lords and their armies. The few surviving witnesses described an epic fight between the Lords of the Abyss and the God-Emperor, which ultimately ended with the Demon Lords devouring the Living God.

The Man Behind the God
Although the Imperium used all available resources to remove all mentions of the mortal lives of the Living Gods (since it is far easier to worship an all-knowing divine being than a fallible mortal), there are still quite a few elves around who lived before they attained divinity. Still, only those well-versed in history would know the original identity of the Living Gods.

Based on their recollections most scholars believe that the God-Emperor was originally Emperor Octavius Augustus, who took power around in the late 70s during the Century of Conquest. He oversaw the end of the Unification of Aegeron, while somehow acquiring the knowledge to first prolong his life and then to ascend to divinity.