History in Ysterra is not a single record. It is many — kept by different peoples in different systems, measured against different celestial events, and shaped by the priorities of whoever was responsible for the recordkeeping. The Calendar of Arkenal is the most widely used timekeeping system across the continent of Insaris, and it serves as the primary reference for dates and eras throughout this guide. But its dominance is a product of Intrescan political influence, not universal agreement, and it was not the first system devised, nor is it the only one still in use.

Beyond the calendar itself, the historical record of Ysterra is uneven by nature. Some eras are documented in exhaustive detail; others survive only in myth, material evidence, or contested accounts of written traditions. The further back the record reaches, the more it depends on interpretation. Scholars may disagree not only about what happened but about when, in whose accounting, and what it meant.

This section collects what is known — or what is broadly agreed upon — about the passage of time in Ysterra: the calendar systems that structure it, and the timelines that attempt to make sense of it. A world as old and as varied as Ysterra does not yield clean histories, and any account that claims otherwise should be read with suspicion.