Astral and Umbral Eras

The First Umbral Calamity marked the beginning of modern history on the star, heralding the First Umbral Era. While scholars once debated on the elemental aspect of this Calamity, the coming of the Sixth Umbral Era allowed scholars to determine that the First Umbral Calamity was one of wind─possibly in the form of terrible hurricanes, tempests, or tornadoes.

The Second Umbral Calamity came on the heels of the First Astral Era, an age where mankind learned to forge stone tools and established settlements and towns, which grew into kingdoms that soon went to war, each seeking to expand their domain. To forge their tools and weapons, mountains were gutted and skies blackened.

Nature was despoiled for countless years until the balance tipped. Volcanoes spewed black smoke that covered the skies and plunged the realm into eternal darkness. Bolts of lightning rained down from the skies for a full year and a day, forcing mankind to seek shelter in underground caverns that became breeding grounds for pestilence. In their desperation, the people prayed for salvation, giving birth to the earliest forms of magical incantations.

The Third Umbral Calamity resulted from the dramatic shift to religious worship in the realm that followed the decline of kingdoms and discovery of magic. These churches became as corrupt and powerful as the kings that preceded them, and their desire for control began an age of holy wars, witch hunts, and genocide.

Theologians believe that the gods grew weary of mankind's hubris and decided to humble them. The sun grew large and an intense heat parched the land. Wildfires spread, reducing fields and forests to wastelands, the people stricken with famine. Fossil evidence found in the desert Grand Wake in Thanalan suggests the deserts that now make up southern Eorzea were once a lush grassland lost in the fires of this Calamity.

A man named Xande establishes the Allagan Empire in Eorzea. Xande conquers much of the known world, save Meracydia, before his death.

The first Umi no Majo, Kurikuchi, is selected and is tasked with going to the world above the waves to bring back resources and knowledge for the Shinkai-min. She has come to be known as the Tea-Bearing Witch.

As Allagan empire experimented and discarded on their "lessers" some of the enslaved Miqo'te that were "decommissioned" from the aetherological experiments and left to die made contact with parts of the First Brood. This meeting eventually resulted in the formation of the Four Fae Courts. This process will last through the next Umbral Era.

The Fourth Umbral Calamity or Calamity of Earth brought the fall of the ancient Allagan Empire that dominated the Three Great Continents throughout the Third Astral Era. The ground beneath the Syrcus Tower gave way and set off a chain reaction of tremors that shook the entire realm, toppling mountains and tearing the land asunder.

The Age of Endless Frost is an ice-age where the world of the Source was completely frozen over.

During this time, seas that turned to ice provided passage to Eorzea. Foreign fauna migrated to Eorzea and was followed by hunters, the Miqo'te tribes — the ancestors of the Miqo'te who were banished from Eorzea millenia prior by the Allagans. 

The Sanctum of the Twelve dates back to this time period.

The Sixth Umbral Calamity brought an end to the War of the Magi that waged for two and a half centuries. Not long after, the realm's scholars and seers brought word that a massive flood was about to occur, believed to be a result of the overuse of the land's ambient aether by white and black magi leaving an overabundance of water-aspected aether.

To stem the realm's tumultuous aetheric currents, the remaining magi of Amdapor and Mhach collaborated to create a massive ziggurat. These magi, with the aid of an Elezen fencer named Count Ganelon, founded the art of red magic to preserve their respective arts without need of ruining the environment.

After the Umbral Calamities of all six elemental aspects had occured, it was thought that Etheirys would no longer need to fear future Umbral Calamities. However, this was not the case. As foretold by the Divine Chronicles, a seventh Umbral Calamity would occur.

Louisoix Leveilleur was one of the only scholars who believed this prophecy and formed the Circle of Knowing along with several of his colleagues to try to prevent it.

Using a lunar transmitter, the Garlean Empire attempted to harness the power of Dalamud in their Meteor Project, and eventually, they were able to pull Dalamud from the sky, using the power of other Primals to fuel its descent. As Dalamud drew closer to the surface, it burst open, revealing the imprisoned elder Primal Bahamut.

Bahamut began its attack, blasting the surface of the world with its Teraflare. Meanwhile, Louisoix's Circle of Knowing prepared, praying at altars to the Twelve around Eorzea in order to channel their power into himself, allowing him to summon himself as the Primal Phoenix.

With this power, Louisoix was able to defeat Bahamut before dispersing his power back to the realm to help speed its rebirth. However, Bahamut's attack had already weakened the barrier between worlds, and this event brought about the rejoining of the Seventh shard to the Source.