The history of Arbre is inspired by Earth's history while diverging in some critical areas. It is told throughout Anathem in both the novel and in additional texts, such as the added chronology in the Introduction.
In historical Arbre dates, the year Zero is the year of the Reconstitution. Years before reconstitution are denoted using negative numbers; years after Reconstitution are listed with the suffix A.R., which stands for After Reconstitution.
Pre-Mathic Age Edit
-2700 Life of Diax.
-2621 Orithena destroyed by volcanic eruption. Beginning of the Peregrin period. Many surviving theors move to the city-state of Ethras.
-2600 to -2300 Golden age of Ethras.
-2396 Execution of Thelenes.
-2335 Death of Protas.
-2272 Ethras forcibly absorbed into Bazian Empire.
-2204 Foundation of the Ark of Baz, a religion.
-2037 Ark of Baz becomes state religion of the Empire.
-1800 Bazian Empire reaches its peak
Old Mathic Age Edit
-1472 Fall of Baz, burning of its Library. Surviving literates flock to Bazian monasteries or Cartasian maths.
-1150 Rise of the Mystagogues.
-600 Purging of the Mystagogues.
-500 Dispersal of the mathic system. Theorical advances start the Praxic Age.
Praxic Age Edit
-74 The First Harbinger.
-52 The Second Harbinger.
-38 Proc's work repudiated by Halikaarn.
-12 The Third Harbinger.
-5 The Terrible Events.