Great Unification

The Great Unification was the event that saw all of the land and peoples of the planet Earth politically united under the Averte Statum. The event was significant due to it being the first time in history that the whole world was under the control of a single government.

History
The Great Unification occurred at the end of the Century War, after the inclusion of Canada, Australia, the Afghan Empire the Pitcairn Freehold the Pact of Isles into the territory of the Averte Statum.

The year in which the Great Unification occurred was declared Year Zero or, and the Standard Calendar was created based on this year, with historical occurrences before and after were dated relative to this event in all official documents.

In Year Zero, the many territories of the Averte Statum still held semi-autonomous status as Dominions, Freeholds, Commonwealths and Autonomous Regions. The Pact of Isles was also granted a degree of autonomy.

However, number of months after the Great Unification, the Averte Statum leader, Demanarch, was assassinated by British Queen Elizabeth III. His son and successor, Ultharch, dissolved all subnational territories and removed all autonomy and privileges of local administrations, bringing all the land of the Earth under direct Averte Statum military control.

Thus, the era of direct Averte Statum control over all the worlds affairs only began in 1 AU, not in Year Zero.

In addition to this curiosity, there was in fact a territory that remained independent of the Averte Statum during and after the unification, namely the Coulman Stronghold, a formerly Australian territory in Antarctica.

After the Great Unification began the Dark Ages, which would begin with the Black Years under Ultharch and see the reigns of Raedarch, Yeldrarch and Treonarch.

Calendrics
The year of the Great Unification was declared Year Zero. All years prior to this are dubbed BU (i.e Before Unification) and all those thereafter are dubbed AU (After Unification).

Year Zero itself can be written as Zero, 0, 0AU, 0BU or GU (i.e. Great Unification). 

The century preceding the Great Unification (and during which the Century War occurred) was known as the First Century BU and the century after was known as the First Century or First Century AU.