https://cubicle7games.com/en_EU/warhammer-fantasy-roleplay-sylvania-setting-guide
“In time, humans ventured into the mountains. The primitive
Fennone tribe settled the foothills and valleys on the periphery,
building roundhouses and ceremonial sites beside the Rivers
Draken and Senk. Their kings dwelled where Castle Senkhof
stands today, and local legend has it that King Drannus
retreated into the foothills rather than meet Sigmar’s emissaries
when they sought alliance against the orcs and goblins. The
Fennones disappeared from Imperial history, though Sylvanian
legend holds that most of the tribe were carried away by dwarfs
to perish in their mines.”
And later:
“The Masters’ Hollow
A small basin ringed by impressive stelae, engraved with an
abased form of Khazilid runes and pictograms showing humans
interacting with dwarfs with braided beards and tall helms.
The dwarfs of Zhufbar shun the Masters’ Hollow and refuse to
answer questions about the stelae or dwarfs depicted on them.”
It seems CDs enslaved humans and let dwarfs take the fall.