aka Age of Antiquity, Time of Demons, Age of the Old Ones, Era of the Elder Races
The "Time Before Man" describes the era prior to the emergence of man and the birth of the elven and dwarven races. Legend, myth, and speculation are the only things that describe this period.
A common Mythosan mythological theme is that existence continually cycles and that the creation of a new world follows the destruction of the old. Therefore, this world may be the rebirth of a previous world, which itself was the recreation of another; no one knows how many times this has occurred or how long it will continue, if not forever.
A Paradisal Time (-10000)
In any case, in the beginning (in this beginning), Mythosa was a paradise. It was home to the Earth Mother, her consort Cerunn, and the spirits of nature and the elements. Vast forests, mountain ranges, oceans, and plains covered the world, which had both an overall temperate climate and enjoyed an eternal summer. Life thrived, with all manner of flora, fauna, and the ancient races: the artistic Husdala, the intellectual Nepharim, the industrious Trussak, the clever Yaat, and the peaceful Selarinn. Things were good, life prospered, and serenity reigned.
Paradise came to an end when the Old Gods came.
The Outer Gods (-9000)
No one knows how they gained entrance to Mythosa, but recurrent themes suggest the Nepharim were responsible. They came from the darkness beyond the world - eldritch, horrific creatures, completely alien in their thinking and appearance. They are commonly referred to as the Old Gods, but also as the Outer Gods and the Gods of the Outer Dark. They arrived with their dark minions and took dominion over the world, enslaving the indigenous races (save for the Nepharim, who fled to another plane). They then created new races by warping and twisting animals into creatures capable of worshiping them, such as the Sith'aal and the Kylithians. These beings created great empires, all dedicated to worshiping the Old Gods.
Creation of the Divine Host (-7000)
Distraught at what had happened to their world, the Earth Mother and Cerunn rallied the remaining creatures and fought back. Their initial attempts to combat the abominable invaders ended in failure. Realizing that the forces available to them were inadequate, they drew upon the energies of the world to birth divine beings to aid in the struggle. These deific children are collectively known as the Divine Host.
The subsequent clash between the Old Gods and the new was the War of the Elders. Many of the Divine Host were slain in the battle but in the end they were victorious. Most of the Old Gods were destroyed, though some proved too difficult to eradicate and were instead imprisoned.
After the war, the world lay devastated and forever changed. No longer a paradise of abundance, it now knew scarcity, hunger, and pain. Eternal summer was no more, as the power unleashed during the war had altered the world - some areas would now know winter, while others would have more extreme summers than before. Fearing more destruction, the Earth Mother banned the gods from bodily walking the earth again and bade them to find a home outside of the mortal plane. She then set about restoring that which had been destroyed, creating new plants and animals to replace those that had been lost. With the help of some of the Divine Host she also created new races to replace those killed by the Outer Gods; among these new races were the Sylvari and the Runir.