To become Senectus, an Ancilla must gain a "position", that is, a role within the Clan from which they serve the clans interests. The Harpies, Whip and spiritual leader (usually Bishop) of the Clan are all Senecti. It is also possible to become Senectus by working for the Prince directly.

Officially, the Primogen is also a Senectus position, but for most practical purposes it is a separate rung on the ladder.