Doomsday

The Doomsday is recorded as the end of the Third Age, bringing about the collapse of Elven empires.
Elven scholars record the Doomsday occurring after the Long Winter, 5 years of frozen conditions across Lutharia. With widespread starvation and suffering, Milisaari writes that eventually day turned to permanent night with many believing that the Sun had become extinct. Millions died as a result of the freezing conditions and even more met their death as a result of starvation.
After months of darkness, a bright star eventually appeared in the darkness and hope began to spread that the Gods had seeded a new Sun. But this was to be a false hope when the bright star erupted into the sky's and raining fire. 
The meteorite that slammed into the Marinoan Ocean, caused the seas to erupt flooding the landmasses of Lutharia. The giant waves was followed by massive earthquakes and then a thousand eruptions of volcanoes, spewing fire and rock across the planet.
The hardest hit continent was North Orentia, with Elven cities reduced to rubble. The Elven populations of North and South Orentia, which had numbered in the tens of millions had been reduced to around two million and of those that had survived the Doomsday event now suffered from what was to be known as the Lava Plague, an illness that appeared to only effect Elvenfolk and would see a fever strike hard and fast and resulting in burning blood erupting from all orifices.
Those that remained unaffected trekked eastwards where word had spread that Ortovia has been spared the worst of the disease and devastation. Of the few Elven ships available for the thousands of refugees fleeing east, few managed to cross the Valenyia Sea and those that managed to reach Ortovia were turned away, as the High Guardian of Rhiongynaddi declared the islands closed. Some found salvation in Tanwynol and some sailed eastwards hoping to find land.