Aurestalia was a polity containing a wide range of nobles who would elect an emperor after the previous one died. After a succession crisis about sixty years ago many nobles became de facto independent or started expanding their realms at the cost of their neighboring nobles within Aurestalia. While originally the conflicts were supposedly about succession the region is largely known for its low scale low intensity but persistent warfare.
Humans have lived in central Kahara for millennia. Originally the region was under the control of Valland but over time became more independent.
About 340 years ago Aurestalia evolved into the elective emperorship it had become known for.
About 60 years ago the current emperor had arranged for his unborn son to be the emperor after him. Unfortunately the emperor died before his wife gave birth, creating a succession question. The nobles were unable to agree on a new emperor and the succession question turned into a succession crisis. While the son retained control over his personal lands, which were quite substantial, many other nobles used the opportunity to weaken Aurestalia's central authority.
The son would eventually be proclaimed emperor, and reasserted control over some of Aurestalia, but the central control of the empire had now been weakened and many nobles paid only lip service to the emperor.
Eventually with his death and his son rising to the emperorship the decentralization caused by the succession crisis had simply become the new status quo.
Most landholding nobles in Aurestalia are quite minor and not particularly wealthy, able to field perhaps a few dozen knights for any campaign. Many wealthier nobles are able to bring more soldiers to the field and regularly hire mercenary companies for the duration of a campaign.
The emperor is able to call upon significant military power, but much of it is at the whims of nobles who answer to him and thus less than completely reliable, hampering his ability to bring Aurestalia back under his control. The emperor is still the greatest landholder in Aurestalia, holding much land personally.
The region sees frequent low intensity, low scale conflict between various nobles and whatever alliances they can mange to put together. Often these are alliances of Aurestalian nobles, but occasionally outside powers will attempt to intervene with their own interests in mind. In theory the emperor is obligated to protect all of Aurestalia from external threats, but this has not always been done and has further injured the perceived legitimacy of the emperor.
Generally speaking, the emperor is too busy managing internal affairs to be much of a player in the affairs of other kings and emperors.
Aurestalia manages to control a great amount of land in the center of the region. Roads and settlements which are able to remain safe are able to profit from this trade. The most common path through the region goes through the crown lands, further benefitting the emperor.