Around 3176 SD, two centuries before the present, the Tarkhon general Klor marched into the southern Eronia Range and did not stop until no one was left to hold it. The campaign ran seven years. When it ended, the passes that had been worked and defended for longer than anyone could reckon belonged to no one, and then to Tarkhon.
It was extermination, not conquest. Conquest leaves a population to tax. Klor left empty valleys: villages burned to their footings, the terraces that had fed them gone to scrub within a decade, the toll-gates that once taxed every caravan through the high passes pulled down and never raised again. The handful who reached neighboring lands carried out the account of it and little else.
Tarkhon's imperial histories call the campaign the Pacification of the Eronia Range, and the empire has held that southern frontier since without losing a soldier to it. What manner of man conducts such a thing, and how the empire honors him, is the matter of his own entry; see Klor the Blood Lord.
"They write that he pacified the range. A range is rock. You do not pacify rock—you pacify the people on it, and the only lasting pacification is the kind that leaves nobody to ask after. He counts the cleared road. I count the valleys nobody comes down from." — Pembling of Grendenheim, Annals of the Seventh Dawn, c. 3330 SD
The cost was deferred, not cancelled. Scattered south and east, the descendants of the cleared passes keep the names of their dead villages and the name of the man who emptied them. More than one regional power took survivors in, and the grievance has compounded across two centuries into something Tarkhon has not yet been made to answer for.