Five Great Nobles

Five Great Nobles (五大貴族) were a group of noble families that once had great influence in the Baharuth Empire.

Background
The Five Great Nobles were once prominent members of nobility in the Empire who were once the pillars of the Empire. However their end came when one of their own, the mother of Jircniv Rune Farlord El Nix was accused of assassinating the Emperor. For the crime, Jircniv's mother's family was eradicated. Soon after Jircniv's brothers were killed one by one, followed by his mother. A power struggle ensued, where several aristocrats along with the Great Nobles were cut down by Prince Jircniv. Those Great Nobles with private armies were ordered to send them against the Re-Estize Kingdom and had all those upkeep fees squeezed out of them. As a result, their might was gone, and all that was left was a handful of pitiful families. There were many families who tried to rebel or even those who disobeyed the Emperor were no longer existed. They were all killed down to the last child. And it was this cruelty that earned Jircniv the epithet of the Bloody Emperor. His rise as the Bloody Emperor coincided with the falls of noble authority and the centralization of power in the Empire.

The Invaders of the Large Tomb Arc
The Five Great Families were referenced by Foresight when talking about Arche Eeb Rile Furt's financial woes due to her parents loss of nobility and denial.

Strength
In the Web Novel, the Five Great Nobles were composed of Margraves whose purpose was to protect the borders of the Empire. Being sponsored by a Great Noble carried weight. There were many types of Great Nobles, some with good reputations, and others with bad rumors plaguing them. Just like how there were black and white companies.

Trivia

 * During the reign of the Blood Emperor there were originally five, however three of the nobles were removed due to their level of authority.
 * In the Web Novel, the remaining Great Nobles and many others reached out to General Ray, Ainz Ooal Gown's subordinate, to ingratiate themselves with the Archduke.