Patrician: The leading families of the Empire – including the Imperial family and the Senatorial sub-class. Own most of the land and wealth in the Empire. 

Equestrian: Lesser nobles. Often wealthy and can maneuver their families into the Patrician class – usually by marriage or outstanding service in the Legions. They make up the bulk of the Legions cavalry and junior officer class, but it is not uncommon for poorer Equestrians to join as Centurions. Citizens must purchase an officer’s commission; cavalry troops must supply their own horse. 

Plebeians: The rest of the Empires citizens comprise a variety of sub-classes: merchants, small farmers, shop owners and all the way down to beggars. All citizens who are not noble are considered Plebeians by the two classes of nobles. As with Equestrians, a Plebeian can through wealth (merchants), or outstanding military service (usually as Centurions) move up in class. Technically any citizen can purchase an Officers commission but that is discouraged for citizens not from one of the noble classes. 

Non-Citizens: People with very little rights in the empire. Prohibited from owning land or serving as anything but auxiliaries in the Legions. Free movement through the Empire is also restricted. Citizenship can be granted by the Emperor or the Senate. If an individual Senator can grant citizenship, is a gray area. 

The Empire is a martial society. From Plebian to Patrician, there are military families where not joining a Legion is likely grounds for dis-inheritance. Leading Patrician families nearly always send their sons to the military – even if for purely political cachet. The ‘Bounders’ as apposed the ‘Competent’ as one auxiliary classifies them. 

The Empire is patriarchal with all the usual divisions between the sexes that accompany such  societies: the army is only open to male citizens with even the battle mages being all-male, the Senate are only men, and the supreme ruler is an Emperor (they have been ruled twice by an Empress). Marriages at the Patrician level are political with even marriage in the lower classes often being contractual affairs.