Eras
Some of the finest sages in the world have tried to split its history up in a number of eras and given them descriptive names. Very little is known of the earlier ones but these are their best guesses.
First Era
Almost nothing is known of this time, writing was not invented and almost nothing from this far back has survived. The little that is known comes from sources from the next era.
The Primordials appear but are defeated, causing much upheaval. Gnome sages call this the Desolation and say it created the Sarodin Sea.
Era of Strife
A time of almost permanent warfare, countries are ruled by priests, not kings. The first mention of dragons and dragon gods.
Uyots is a god from this era.
The Final Order was founded.
The Tecuani Tecpatl, the Loxotl Amulet, and the Vigilant's Primer are from this era.
The first language, known as Ancient, is used most, though other languages also exist. Metallurgy is invented and used in the south on a small scale.
At the end of the era the Endless Night throws the world back. What it exactly was remains unclear.
Era of Renewal
Many technological improvements are made, most countries are now feudal in nature.
Rades is a god from this era.
The language of the world changes to Common and is used almost throughout.
The Collapse shakes the world and ends the era.
Era of Refinement
The current era. See a short-ish history of the world from the Collapse till now for more information.