Concord
The Garou left Humanity to their on devices, instead opting to control them more subtly. They separated their societies, and created the Western Concordait. Humanity has since consciously forgotten about them, but the supernatural Delirium remains.
Prophecies of Shadow
In 1230, a Red Talon prophet named Songs of Shadow emerged from the Umbra, and travelled across Europe delivering prophecies. Each of the ten tribes received a prophecy. At the time, they were deemed unimportant and unclear, as they were told to be related to future events. Historians of the Silver Fangs and Shadow Lords claim to have transcriptions of all ten. However, none of the tribes can agree they ever came to pass, or if they are even real. Some Garou believe the answers to the war do not lie in the prophecies.
War of Rage
For unknown reasons, the Garou waged war on the Fera, and wiped out a majority of them. Perhaps they thought they alone could carry out Gaia’s will, or simply lost control of their Rage. In response, Gaia gave Humanity silver, and they fought back. In response, the Garou formed the Concord.
The Veil
The tenet in Garou culture that dictates Humanity should not be aware that Garou exist. If there is even the slightest hint a human is aware of the existence of the Garou, the Kinfolk will move heaven and earth to prevent the knowledge from spreading. Either by destroying a recording, or killing a witness.
Note
Glass Walkers and Children of Gaia avoid spilling human blood in these instances if possible, as they believe it is the carelessness of the Garou to blame.