The science of chronology has occupied scholars of the Saint Montaigne since the earliest introduction of literacy to the region.  Although in more recent times this noble field of knowledge has been reduced to the mere alignment of different systems of dating with each other and with predictable natural phenomena such as eclipses of the moon and Vottean Quakes, in more ancient times the study of the year was believed to form an entree into the understanding of the nature of reality itself, and discerning the proper year from which all others were to be dated was considered indispensable to a proper organization of human society.  As the poet says,

Tymyara nia, zette beller' ia togellenen.

"Our year the cradle, where lie slumbering the orders of all things"

This approach appealed to the scientist as well as the mystic of the earliest ages, and experienced a revival in the centuries leading up to the time of the Experimental Duchies.  It was in those same centuries that the system of chronology based in the Epoch of Donissi (B.E.D.,"Before Epoch of Donissi" and A.E.D. "After Epoch of Donissi") first gained currency.  Although it traces its origins to obscure and esoteric sects, this chronology, which dates events from the traditional year when Donisso Donissi began writing his Alphabet (according to esoteric teaching, this took place precisely 121,000,000 years from the beginning of time), gained wide international use because all other chronological systems were tied to the history of a particular duchy.  Modern scholarship has shown the traditional date for Donisso Donissi himself to be erroneous (not to mention those earliest strata of the Alphabet which precede him by several centuries), and groups which found cosmic meaning in the Epoch Donissi have dwindled almost to nothing, especially since the fall of the Experimental Duchies, but nonetheless this chronology has remained in use, one imagines mainly through sheer force of inertia.

In remedy of this strange situation in the historiography of our delta, certain scholars have proposed alternative "universal" dating systems.  Among the most popular is A.M. (After Migration), which begins its era in 300 B.E.D. the traditional beginning of the Second Montaignean Migration.  Likewise the chronologies of certain influential duchies have gained some currency beyond their borders.  Among these the most common are the Year of Lacessa (beginning with the foundation of the city in 265 A.E.D., 565 A.M.) and the a.d.c dating of the Duchy of Tesso, which dates from the establishment of rule by the Council of Twelve (1007 A.E.D, 1307 A.M., Year of Lacessa 742). Some have also proposed the foundation of the Duchy of Twaliz  in 1439 A.E.D., as the earliest true Experimental Duchy, or the fall of the last Experimental Duchies some centuries later (dates vary), as organizing points for a new chronology.  Despite their various proponents and advantages, none of these is any serious rival to the Epoch Donissi system.

-Sir Eadmon of Lacessa