The Milky Way Galaxy has become similar to Earth in the early 1000's. Considered colonized and controlled, however far humanity has spread, it is still nothing compared to the sheer size of the Galaxy.
Currently, humanity has grown to its largest in all of human history. With over 55 million documented colonized worlds and 5 quadrillion documented people. However it is suspected that another 5 million worlds have been colonized in hidden parts of the Milky Way.
Officially, the Milky Way Galaxy is under the singular control of the UPG. Which is enforced by the CMC. It has remained that way since the formation of the UPG at the start of human expansion. Although singular worlds have on occasion tried to resist their leaders, said resistance has never lasted long. Often due to a quick and brutal suppression by the CMC.
This control is often credited to the rich and powerful. This is due to the almost complete eradication of reliance on labour. Unlike in the past, when the poor would work the fields and mine the earth for resources, instead, the rich and powerful control through automation. By owning the companies that build automated farming and mining machines in automated factories, the upper echelon of Humanity have eradicated any chance of a unified uprising or sudden shift in power.
Although often considered the worst possible outcome of capitalism, it cannot be denied that there has never been a longer era of peace in human history.
With humanities wide spread colonization of the Galaxy, came the spread of the Houses. Each House claimed the mantle of a world or sometimes a system, which they would make their home and rule from a ceremonial position. Like Royalty of times past, the Houses are considered what humanity used to be called kings and queens.
The start of the war brought about a new era of unity. A new reason to set aside petty differences. With almost every world and every person dedicated to aiding the war effort.
Some worlds have suffered to then point of being reduced to literal asteroid fields. However for the most part, the worlds of human controlled space have thrived from the need to aid the effort. The center worlds of the Inner Colonies have known almost know change. Operating as they have for over a thousand years.