Shattering

From the White Wolf Wiki, the most complete White Wolf reference

The five eras of Changeling history can be divided into the Mythic Age, the Sundering, the Shattering, the Interregnum, and the Resurgence.

Around the time of the Spanish Inquisition and the Black Plague (and the practice of last names coming into vogue), the pressure finally broke, causing the Shattering (prompting large numbers of Fae to either jump ship for Arcadia or adopt the Changeling Way, or hide). Between 1200-1400 AD and 1500-1600 AD, the breaking away of the mythic from the mundane became more complete. The pathway trods between the Mundane world and the Dreamings began to vanish and/or close, as did the routes leading to Arcadia.