The Aes sedai Council is chaired by the Dragon.
The Dragon is chosen by vote of the other Aes Sedai with
the advice and consent of the Three Realms.

This five to twelve member coucil rules over Avalon
making important descissions on matters of foreign policy,
domestic policy, and any matters important to the whole
of Avalon not specifically in the hands of on of the Realms.
The Aes Sedai are specifically charged with the responsiblity
for the health, well being and prosperity of Manetherin proper.

Aes Sedai members are chosen by other members of the Aes
Sedai council and entrance is NOT based on level (although
preferences may exist). Alignment, wisdom, and style are
the primary elements of selection.

The Aes Sedai council then chairs meetings of the Three Realms.
The Three Realms meet and vote to establish the laws that govern
the daily workings of Avalon and Manetherin

Each Realm designs the legislation particular to their
area and may then bring it up before a vote of the
Three Realms to become Law.

Each Realm may also create its own rules and proceedures
to govern its responsibilities. The Belgariad may enact rules
which bind all mages, the Warward sets the rules for the
armies, etc. Each realm independantly creates and maintains
its own power structure.
 

Reguardless of Realm, Body, or institution, ALL institutions
MUST follow the "Law of Institutions" as laid down in the
founding charters. No institution is above this law including
the Aes Sedai, the Church, or even any independant body.
It simply states that no institution may exist that functions
so it is an end, in and of, itself.
All Institutions must provide some benefit to society.
this is the cost they pay in order to reap the gains of
social order, trade, protection, etc that society provides.
There are no exceptions and any institution found wanting
in this reguard by a 2/3 majority, can be dissolved.

This too applies to the goverment of Avalon. If 2/3 of the
population find that the goverment is serving its own needs and
not the needs of the people, nature, or the arcane mysteries
of the world they have the moral sanction to revolt.