is thought to be the oldest series of worlds among the Related Worlds
, and the one that all the other series split off from.
It is known for its powerful Mage
s, who among other accomplishments were the first to discover and categorise the Related Worlds (so it might well have been named Series One regardless).
There are magical weapons made in Series One that can destroy even the strongest enchanter, or strip a person's magic away.
The world Christopher Chant visits with Tacroy in The Lives of Christopher Chant has ring-trains, which hurtle through the air without any track, passing through enormous rings held high above the ground by pylons and spaced miles apart.
Chrestomanci attends the Conclave of Mages in Series One in "Stealer of Souls".