Similar to how Knowledge (local) gets broken down regionally in a campaign setting, Knowledge history gets broken down as well. In the case of the Ign'nikhu world, there's two types for some regions: Knowledge (x history) and Knowledge (x ancient history). Regions on the Western Continent, such as Rin'nikhu and the Land of Lights, are much younger, and were mostly only built after The Dawn of Exploration. This means they don't have much in the way of Ancient History, so that knowledge skill is not offered for them. Some regions on the East coast of the Western Continent, as well as all the ones on the Eastern Continent are extremely old, and some may have broken acient history knowledge skills, such as a north and a south for a region.

 

The simple way to determine which needs to be rolled is if the event took place before or after the Dawn of Exploration. Years on the current calendar are dated with an A.E., which stands for After Exploration, and continue to count up. Before that were the G.D.E. years, which stands for the Great Dragon Extinction, which also count up.

These were the years after the Thousand Year Dragon War that drastically decreased the Dragon population, and is said to have been the extintion of several species of True Dragons. The last 36 years of the G.D.E. years and the first 36 of the A.E. years are actually the same, and they were the years that Rin's adventuring party ventured across the Western Continent and founded many of it's current regions.

 

The Thousand Year Dragon War years are initialed T.D.W., and the damage from the war was incredibly detructive, but unfortunately included most historical monuments, museums and libraries. Very little is known about the years before it, and many dragons only speculate on why it was started. Due to this, even a well researched scholar can't answer much about times before this.