The Cataclysm, and the Following Ages

At the end of the Age of Heroes, Olyxeus II of House Illyrian broke out violently onto the world stage as the harbinger of its impending doom by consorting with the malefic forces of the Void, a plane of vacuous nothingness (or so it would seem for many thousands of years thereafter). Abandoning his old name and embracing the mantle of the Void's avatar, Dark Lord Olyxendir was crowned the King of the Empire of Kheldor after defeating his brother, the rightful king, in a duel. Through whispered promises or bombastic displays of power he amassed a massive cult to add to his nations' army, imbuing them all with the dark strength of the Void. He would let his forces loose upon the world with a single order - to destroy.
Much of the history around that time has been lost following the annihilation of countless peoples and civilizations, many of which we imagine there is nothing remaining to know they ever existed in the first place. Most painfully of all was the Burning of the Library of Telandria - the lost capital of ancient Laelux. We do know that this campaign of destruction continued for two years and several months before Olyxendir's eventual defeat at the hands (and sacrifice) of the fabled Heralds of Dawn.
In the immediate centuries following the Cataclysm, as it all came to be known, an unprecedented and deafening silence fell across the world as the severe influx of the Void's energies into our world poisoned Astraea's leylines and caused all magic to vanish from our world for the next 7,500 years. As a consequence many devices, theretofore commonplace, utilized for transportation (such as teleportation sigils for travel between landmasses) or navigation (aetherically powered vehicles, much like we employ here in modern Borealis) were now non-functional. Likewise, magics used to communicate across vast distances no longer functioned.
Those who survived, thanks be to the Heralds, had no established reliable method to find whatever other surviving factions might be left alive amongst that desolate and apolalyptic wasteland. During that same time, the Nine all but fully retreated from the world - no cleric or devout faithful could feel their deity's presence in the Material Plane. Thusly, Astraea's disparate peoples underwent isolated efforts toward what was immediately and materially achievable - rebuilding what we could, marking the beginning of the Age of Restoration.
The havoc wreaked upon Olyxendir wreaked upon our world only began to heal 2,500 years ago when a zarician priest, Tofari Nwadiwe, was called to bless the birth of a new child and, to his shock as well as the family's, cast the first spell to flow through the long-dead currents of our world in over 75 centuries. Whether he was truly the first to do so is a matter of debate, though his story is the earliest event we at the Archives have verifiably documented.
Following this event, magic flowed slowly through the leylines once again and the Age of Reformation, the current era, had begun.
_{- Elmont Tanier, Former Member of the Blades of a New Dawn and Initiate Scholar at the Ancerides Archives of Borealis}