The Starguild imposed the Starcaste system to control the masses, and it has endured to the present time. This caste system separates Humanity into Starcaste, Landcaste, and Bondsmen, and limits the standing of all alien races. Each of the castes is hereditary, and it is virtually impossible to advance in standing.
Read more about Starcaste.
The Starcaste is made up of the members of the Starguild and their families. As mentioned above, they have complete control of advanced technology. This monopoly ensures their military superiority and guarantees their position.
Read more about Landcaste.
The Landcaste are the servants of the Starcaste. They lack stardrive, but have control of the military, economic, and political offices of each planetary government. Since the Starcaste does not want to be bothered with anything except its own small population, it leaves the details of running the various planets to an assortment of Landcaste Management firms. These are also hereditary organizations, and were formed from those groups which failed in their bids to control Stardrive and the like, but which had enough that they could not be ignored.
Throughout the Imperium, the Landcaste live in high style but are subjected to tremendous pressures; the Starcaste demands the highest of production, but at the same time the Bondsmen are often on the edge of rebellion as a result of being worked too hard. This puts the Landcaste in a very difficult position, and they generally cycle between Starcaste anger and Bondsmen revolt.
As a result of this chaos, all Landcaste firms maintain their own large militaries, composed entirely of Landcaste personnel, and they usually have enough power to dominate the Bondsmen. While their militaries are fairly large, they have no Stardrive with which to threaten the Starcaste, and their weapons use more primitive technologies.
Read more about Bondsmen.
The Bondsmen are the workers of society. Their ancestors wielded no power during the Corporate Wars, and so their well-being was not considered when the Starguild was formed. As a result, they live in a crowded, highly regulated society, which restricts their activities and deprives them of freedom. Revolt against the tremendous power of the upper classes, although a common occurrence, is futile.