The Rebirth of Nerathus
Before The Great Collapse, the dwarven clan Blackcrag had an alliance with Nerathus and generally helped the empire with suppressing the rebellions in its settlements. When Neerun, the capital of Nerathus, was attacked by orcs and gnolls, it called for help from its dwarven allies to the immediate north. Clan Blackcrag did come, but instead of aiding Neerun, it joined in the pillaging, ravaging, and looting, and helped lead to the downfall of Nerathus.
Upon hearing about this betrayal, the other city-states retaliated against the clans stronghold, destroying it, and scattering the clan from its home. The name Blackcrag has ever since been tainted, and any from the clan are scourned wherever they go.