Sidhe who awaken to their faerie selves not only discover their kith, they also acquire knowledge of the noble houses to which they belong. When the trods opened in 1969, allowing many of the sidhe to return to the mortal world, five noble houses came through from Arcadia. Many of them retained the vague sense that their return was forced upon them, an exile from the Dreaming as punishment for deeds they couldn't remember.
Unlike the commoner kith, the sidhe have only been on Earth in substantial numbers since the Resurgence. Nevertheless, the five noble houses quickly reasserted their presence on Kithain society, restructuring it to fit their memories of the old days before their untimely departure. Today, in the aftermath of the Accordance War and the Treaty of Concord, these houses maintain a monopoly on the power structure of the Kithain.
Since the Resurgence, individuals from the eight houses remaining in Arcadia have arrived on Earth, either banished from the Dreaming as renegades and outcasts or else sent to fulfill specific purposes. Due to the action of the Mists, these solitary sidhe seldom remember the reasons for their appearances in the mortal world. Although these loners usually find sanctuary under the aegis of one of the established noble houses, they rarely rise to high positions in their adopted houses since their hosts can never be certain if they are giving shelter to Arcadian criminals or heroes on Earthly quests.
The noble houses take their names from their legendary founders, who imbued their lines with certain aspects of their personalities. Thus, members of one house share some characteristics, although individuals may vary widely from the stereotype.
Politics and intrigue are meat and drink to the sidhe. Divorcing a highborn from his political affiliation is nigh impossible. When a house suffers, all sidhe within that house suffer. In fact, most sidhe in the world today have been exiled from Arcadia because of their house affiliations.
This affiliation can define a sidhe's personality, his politics, and his approach to rulership. Although commoners can swear allegiance to a house or even receive titles in one, their bonds are never as strong as that of the sidhe. Fealty to a house is a measure of honor and pride. Even the circumstances under which a Seelie sidhe becomes Unseelie can be influenced by this alliance. During character creation, commoners can have membership in a house, but only with the permission of the Storyteller.
Each house bestows a certain benefit (called a Boon) to the Kithain who support it. However, for each Boon bestowed, there is also a Flaw, a disadvantage that the members of the houses must endure. Many houses have conditions that they require of their members; upholding these is second nature to the highborns.
There are also countless stories explaining why the houses returned to Earth during the Resurgence. Unseelie believe that the sidhe fled Arcadia because it was dying. Extremists even believe that by questing throughout the mortal world, changelings may find a way to restore the balance between the two worlds and reopen the gates of Arcadia. Seelie and Unseelie debate how this balance should be restored.
Some sidhe have memories of being sentenced to exile, but always have distorted memories of who or what exiled them. Perhaps it was the High Lords of Arcadia or the High King. Perhaps it was for another reason. The answers are hidden in dreams, yet the ruler of each house has an explanation that he or she firmly believes. Whether these explanations are true is highly debatable.