Many songs and epic poems are still heard today that tell of the cataclysm of the Moonfall. The intervention of more than two millennia, and the more recent calamity of the Darkness, have resulted in disagreements small and large in the tellings.
But all begin with how Great Mal chafed at limitations placed on him during the Years of Concord, and aspired to put his stamp upon all of Gaea. His subversion of the Concord was subtle and undetected at first. Great movements and conquests of orcs were thought to be of their own doing, but in fact they were but Mal’s proxy. Eventually Mal’s genocidal hostility to the Eldar, the children of Lis, and his first suborning, and then enslaving, the Longbeards, the children of Meh, betrayed the depths of his plans to Lis, Meh, and the rest of the Great Powers and the Powers Minor. When commanded to humble himself, Mal openly rebelled, beguiling a few of the lesser Powers to join him, but they could not stand against the opposing Powers. At the very end Mal was said to claim, falsely, that as he was the core of the making of Gaea, and so could he unmake it. A large chunk was torn from one side of the moon, Selene, and flung towards Gaea, taking days to approach. Tremendous spectral forms of Mal and Meh filled the sky, grappling with each other, while titanic bolts of power shot between Gaea, Selene, and the approaching shard. These struggles may have slowed it, but not deflect it.
And when it struck, the world was remade. There is no record of an actual catastrophe that must have resulted. It was if the world had gone from one instant to one thousands of years later. No smoking crater, but there is a gigantic new sea, almost circular, said to be filled with the Tears of Lis as she sought to overcome the marring of such a great work as Gaea. The greatest center of Eldar civilization, Atalante, had been within what was now the Lister Sea. All other cities, save one, became dusty ruins. Rivers changed course, great canyons dug, and mountain ranges now existed where none had before.
And there were casualties. Almost nine in ten of the elves were dead, and the remainder sundered into four different kinds. The other Kindreds suffered almost as much. The dwarves threw off their shackles, and claimed Plii as blood price, though this did not stand. The orcs were scattered over the wide world, small tribes that threatened each other as much as any other people.
Mal no longer was in urXron, though no mortal knew the details of his fate, whether consigned to the Eternal Source, or expelled to the Outer Dark. His hierarchy and agents on Gaea were overthrown, his Realm harrowed of his minions.
And thus a new epoch was proclaimed, the years AF, after the Fall of Moon and Meh.