The High Nobility was the upper echelon of the Noble social class in the Goldenbaum Dynasty's social hierarchy. High Nobles were men and women from the oldest and most powerful noble families in the Galactic Empire. It was from the High Nobility that most of the Empire's most powerful political leaders hailed from, not because of merit but because of blood.
Ironically, when Rudolph von Goldenbaum first established the aristocracy, it was something of a meritocracy: men and women of exceptional ability could, at times, be elevated to noble rank. This provided early Imperial society with a degree of upward social mobility, allowing the culture of the Empire to stay dynamic. Eventually, however, the nobility became a stagnant social class, which could only be inherited through blood. This gradually increased the resentment of the lower classes, and eventually led to the Exodus of Arle Heinnesen, and a rise in republican protestors and social reformers. The High Nobility, however, was ruthless in destroying anything that might endanger its authority.
In the Imperial Civil War, most of the High Nobility sided with prince Otto von Braunschweig. The more liberal nobles of the social-reform mindset--sided with Reinhard von Lohengramm in the war, but at the war's end, regardless of whether they were High Nobles or Low Nobles, the nobles that had rebelled agienst him were stripped of there titles and wealth. Those who did not they were allowed to keep there titles and wealth.