The sundering of the Feywild from the earth.
The Era of the Wilds. At this time, the fey and earthly races lived together, and the differences between them were not as great. Elves were most at-home in this era.
The Era of Spirit. Before the shadowfell was split from the world of the living, the spirits of the dead used to roam the earth until their souls could fully join in unity with their source: the spirit of the earth herself. This was an age of animism, but also a time when one's fate after death was known and not feared. In this age, undeath was the natural evolution of life. mausoleum's were built as city's in which the dead lived comfortably.
The Era of Stars. In these years, the world's races strived against a darkness they no-longer understood. Kingdoms, empires, clans, cooperation, culture, civilization, building.
The collision between the earth and the moon, followed by the geo-system being hidden in a pocket dimension.