I'm much more fond of claiming the power than starting in the position of power, but if you really need an emperor...
Name :Hedemoden Sirias Safaran
Personal history : Hedemoden, son of Sirius of Safaran dynasty, Prince of Safaran Gate and Lord of Pharsis Expanse - grand title for a scion of a grand family, Hedemoden inherited his position as a lord of the dynastic estate during the civil war and distinguished himself in several campaigns that defended the home sector and then took the fight to the enemy, striking at the imperial throne world in a daring assault and decapitation the usurpers in a swift assault. Subsequently, by the virtue of military occupation ,the reality on the ground made Hedemoden the Imperial Regent. As the fires of war waned, the easing of conflict allowed for diplomatic settlements and subsequent assuming of the Imperial throne. Despite his martial career, Hedemoden fancies himself a diplomat, and drawing on the wealth of the Expanse he is able to support his social efforts as well as cultural and architectural ambitions.
Sector description and history : The Safaran Gate and the Pharsis expanse, despite their astronomical distance, are usually treated as a single sector, as the Gate stands as the sole waypoint and world between the galaxy at large and the Expanse, which hides within a post-supernova nebula, with a single safe passage leading through out the Gate. Worlds of the Expanse are in majority cases barren worlds, and those harboring a breathable atmosphere are in majority of cases spent planets, whose native life already expired in the harsh conditions of the nebula, leaving behind vast deserts, but also unconsumed deposits of minerals and biological residues. As a result, the sector draws its wealth from mining, refining and the trade that flows in and out and is taxed at the Gate, with vast tolls charged on those willing and eager to access the fabled riches of this unusual pocket of the galaxy. Merchants ferrying goods between various worlds, trading ores, spices, fuels and minerals are not uncommon and usually a serai (merchant outpost) of the Pharsis merchants can be found within the imperial territory as a result. Their opulence and wealth are near-legendary and "living like a Safaran" became a standard description for those who were very, very rich.
While there are many local fiefdoms and nobles that occupy some domains, they all swear allegiance to the Prince and hold him as the ultimate sovereign of the sector, counting their blessings and thanking each generation of their overlords for the bestowed privileges, be it mercantile or political within the Safaran household. Many of these nobles subsequently serve as officers in the Genoluk regiments, which are Safaran standing army. Genoluks are gene-engineered troops, borne out of household servants that were upgraded and increased with each generation until they became an army. Either vat-grown or gene-implanted at young age, all trooper and NCO Genoluks are slavishly loyal and fearsome, forming a vanguard and personal bodyguard of each Safaran or nobles which were granted a privilege of Genoluk bodyguard. Despite their fanciful uniforms and armor, they are deadly with almost all conceivable conventional weapons and use camouflage or field uniforms when needed. Despite their elite status, Safaran try to field them in large numbers where possible, placing thme as marines and ground troops alike. Many of the Genoluks are modified to be pilots and navy crews as well.
Imperial Description and history : Throughout their long history, Safaran dynasty had lot of blood relations with various emperors and played the dynastic game as soon as it began, themselves a beneficients of an imperial grant on then unexplored Expanse. Their subsequent connections and continuous influence meant that as chaos descended and the Imperium crumbled, Hedemoden was well-placed to seize the throne and proclaim himself as the ruler, with just enough history behind him to back up that claim. The Safaran dynasty was long synonymous with power within the Imperium but only now it materialized itself as the actual Imperial court. Despite their connections and influence, Safaran always relied on their own resources and for a long time held disdain for both the Guard and Imperial military, seeing them as inflexible and ultimately unreliable in the long term. While some of those fears were confirmed during the conflict, their power was undeniable and as such, a grudging neutrality was assumed towards them.