The duende were an old race long before men ever came to settle the fields and forests they called home. Despite some of their number possessing supernatural powers and abilities, duende were, by and large, a peaceful people, given to wonder and merriment. So, when the men came, the duende characteristically saw them initially as wondrous new arrivals rather than a threat to their way of life. For centuries, they lived among the men, insinuating themselves into human society and doing things that humans did.
The peaceful – if secret – coexistence did not last forever. No one knows how men discovered that they were living with supernatural beings, but discover them they did and what followed was almost a century of fear, distrust, and ultimately hostility.
Since they had been living among humans for such a long time, many of the duende had all but forgotten about their true nature. These ones were called the katao, and many duende grieved for their loss. The rest, those who remained mindful of their true nature, over a period of more than half a century slowly withdrew from human society. Among the mindful duende, this was called the Time of Sadness.
And still the men kept coming. Expanding their farms and cutting down trees, men slowly but surely – if unwittingly – drove the duende to near extinction. And then, around four hundred years ago, men became openly hostile to the duende, ending the Time of Sadness and ushering in The Great Migration.