After deposing the king and cowing the nobility, the Ruling Coven launched a surprise war on the elven kingdom of Aerelen. This forced the Covenate to unite against a common enemy. However, Aerelen had sufficient feyweaver mages who were able to resist the magical assassination tactics that the witches had used so effectively against the monarchy and nobles they overthrew.
After losing too many witches to eladrin mystical defenses, the Ruling Coven shifted to a more traditional military approach. They then cycled through a number of generals before settling on the surprisingly-capable battlefield command of Violet Thornhallow, at the time a young, lesser-known member of the Ruling Coven. Violet ultimately managed a victory, and the conquest of a few long-coveted borderlands was secured, along with thousands of elven prisoners. The elven women proved lucrative to sell as slaves across the Covenate.
Now, whenever the Ruling Coven plan a campaign, Violet takes charge. She is largely thought to be weaker in personal magical power than some of the elder witches on the Ruling Coven, but her military capabilities have kept her around as a useful leader to have on hand. All witches on the Ruling Coven are putative 'equals', but few know who really pulls the strings within their cloistered politics.
Over the last twenty years, the Ruling Coven has waged several wars against Aerelen. Each war they seize more contested borderlands, raze more elven settlements, seize more slaves, and bleed down both the elven army and their own nobles' mustered forces, ensuring that no one abroad or at home is strong enough to challenge their rule.