The Free Companies of Khatovar were mysterious groups of armed cultists who left their world Khatovar, crossed the Plain of Glittering Stone, and entered into the homeworld via the shadowgate about 400 years before Croaker's Annals. Their goal was to bring about the Year of the Skulls, to free their imprisoned goddess, Kina.
There were ostensibly eight Companies in total, each using a magic lance as their shadowgate key. Each of their entries into the homeworld was recorded by the librarians of Kiaulune, who also recorded the subsequent return of all but one, back through the shadowgate, onto the Plain of Glittering Stone, and presumably to Khatovar. The Black Company, the last of the Free Companies, had lost its original mission over the centuries and remained in the homeworld. They forgot Kina and that their Lance of Passion was actually a shadowgate key, and became simply a band of mercenaries that migrated slowly northward for generations. This Company would go on to fight to prevent the Year of the Skulls, and would become Kina's most dangerous adversary.
Only the Black Company was identified by name in the Annals. All the other Companies, the ones which returned to Khatovar, were apparently wiped out by the unnamed, hostile, rival kingdom which reduced the city of Khatovar to ruins. This occurred before the Voroshk family of sorcerers created a dynasty in that world.