The government of Arbre outside the maths. During the time of the novel (A.R. 3689 - A.R. 3691) the political situation in the Saecular world is not described in great detail, although a number of clues are given. Arbre has a world government, a Federation of large political units. These "national" units are likely known as Tetrarchies (although there are eight of them). Also mentioned is The Plenary Council of Recovered Satrapies, which may be some type of legislative body; the Eleventh Circle of Arch-Magistrates; and Prefectures.