White Moon is the royal clan of the kingdom of Shan Ke. They reside in White Moon Castle in the Bar Comas mountains.
White Moon is one of two powers in the kingdom, the other being Black Moon. White Moon is the official government of the kingdom, whereas Black Moon (intentionally named in contrast) is a cabal formed by the most powerful guilds in the kingdom. There has been a long history of conflict--both political and physical--between the two powers. As a result of the events of the Forge, the two powers have established a truce--the Pax Luna--and are working together. This does not mean that there aren't still areas of tension and friction between the two powers.
White Moon governs on a platform of personal responsibility and proof. The laws they have established are few, but strong. While there have (of course) been abuses of power throughout their history, they remain one of the most even-handed of monarchies on Lou. They are also, however, one of the most brutal. This is not a contradiction. The core philosophy of White Moon is that each person is responsible for their own acts, and the government has no obligation to protect them as individuals. Shan Ke law is based not on the individual, but on the society as a whole. The laws forbid murder, but not personal duels. They require businesses to be honest in their claims, but will not protect a person who fails to read the fine print.
An example of the philosophy is the "bare blade" precedent. A person may claim harm under the law if they are assaulted in any significant manner. However, as soon as they draw a blade (i.e. use harmful or deadly force) they are considered a consenting participant, and no longer protected. The actual applications are a bit more subtle than that, but that's the basic idea.
While most of White Moon are adherents of the UCT, there is no official religion in Shan Ke. All religions are welcome in Shan Ke, as long as they follow the rules--and those rules are few.