How I Stopped Worrying and Learned to Love Eberron
Gnomish society is bound together by a vast game of intrigue, alliances, and wits. This kind of culture does not give itself to heroic leaders or powerful despots, so when Zilargo came into being, there was much argument over a system of administration and leadership. Eventually, the three largest city-states (Trolanport, Zolanberg, and Korranberg) came to a compromise, establishing their respective leaders as the members of the ruling council, called the Triumvirate. The pyramid structure of elected delegates was based on the administration of the Library of Korranberg.
While allowing the individual Zil communities a fair amount of autonomy, the Triumvirate is ruthless when it comes to perceived threats to the gnomish people. To that end, they direct their intelligence agency, The Trust, to make their enemies literally vanish.