Lily
A planet of incredible resources in a solar system that shares that quality, Lily was once one of the Corporate Worlds, colonized and owned by an Earthly megacorporation, but it broke free and declared its own independence when its corporate overlords grew too greedy, and denied the colonists any representation or recourse. Left as practical serfs, if not slaves, they banded together and threw off the bonds that had been placed on them. Declaring themselves a free planet, they established their own monarchy and aristocracy, based on roles in the Lilyan resistance that threw out the corporate overlords. This awareness of the righteous deeds of their forebears has prevented the still-young nobility from falling into abuses of power, and they are generally liked and loved by the populace in general -- and the romantic flair of nobility has served to spur tourism and immigration to the Lilyan worlds, as well, so it is an aspect that Lilyans are happy to play up, purposefully constructing their towns to camouflage the use of technology and to remind humans of their romanticized history, full of lords and ladies and monolithic stone architecture.
Dominion
The Lily Kingdom spans the seven planets of their star system, though some are as little as small scientific and mining outposts, on planets which are not feasible for large-scale human habitation. It is ruled centrally from the second planet from their star, the primary and most populous world, which also bears the name of Lily.
Governance
While the Lilyan Kingdom has a monarch (they equally acknowledge the ability to rule of men and women, so it may be a king or queen ruling in their own right) they are not an absolute monarch. No Lilyan has a desire to place themselves under an incontestable governance again, so their constitutional monarchy has numerous checks and balances written into it, as a modern starfaring kingdom should. Their nobility sits as one of the primary checks and balances, acting as the primary legislative body of government, checking the executive power of the monarch. In turn, one of the primary checks on the nobility's legislative power is the constitutional principle that they may pass no law that excludes themselves from it, preventing them from taxing non-nobles differently from themselves, for example, or from passing laws that give them special privilege beyond the constitutionally-granted rights of the nobility. As the third branch of government, the independent judiciary is drawn strictly from the non-nobility, and is required to vet all legislation for constitutionality, providing an additional check on the nobility. Checking the judiciary, the monarch remains the court of final appeal, able to grant royal pardons to those that feel they have been wronged by the judiciary -- or to increase the penalties on those that frivolously abuse the right to appeal to the monarch's mercy.
The Lilyan Kingdom does not, at this time, consider itself a member of the Human Alliance, and does not send a representative to the Alliance Senate. They cite the Alliance's inactivity in dealing with the corrupt corporate system that enslaved them as cause for their continued independence, although since their break with their originating corporation and the publication of the reasons thereof, the Corporate Worlds have been careful to not incite any additional rebellions and to be seen to treat their people well.
Economy
While the Lily Kingdom is fantastically productive from an industrial standpoint, its resource wealth being the original cause of the colonization of the planet and system, since the revolution, there has been tremendous effort put in to ensure that the kingdom is not merely another industrial engine. With a call to remembrances of the heroics of yesteryear, Lilyan architecture has been transformed to recall the massive stone structures of the High Gothic period of Earth (which is far easier to construct using gravitic lifting and construction tools), they commonly hold tournaments of skill -- culminating in the annual Royal Lilyan Tournament on Lily itself, one of the means by which new blood can enter the nobility -- and even have modified educational programs to instruct their people in archaic forms of speech, creating an immersive environment that is both as comfortable as any modern world, but evokes an unique and powerful emotional response that has tourists emptying their wallets into the Lilyan economy.