The trouble is that history is not fixed and keeps changing. This is due to a small nexus near Rennes-Les-Bains. Events leak through but are warped and distorted by the field.
Eventually you get a series of alternate histories arranged like planes, but strung though with wormhole like connections. Only a few, mostly from the gnostic tradition, have understood this. Through the "holes" alternate histories appear as myths - King Arthur stories are some of the most persistent.
Kate Mosse's Languedoc series tried to convey some of this, but unfortunately has itself become fiction. Shame, but still a good read.
