The Ddwyrth were created together by the Seventh Ancestor, Stel, aided by the Twelfth and Eleventh.
In the archaeological record they are represented by the Neanderthal, who we consider extinct, but they are not.
Stel was a project manager for the mining sector, so tunneling was one gift she gave her creation.
Her second gift was processing ore, as in smelting, fortging weapons.
Her final gift was steadfstness, to remain true to the task at hand until completed.