Early in Dark of the Moon, the old Lord Coman died without a lordan. Tradionally, his eldest son Demoth would've become the next lord, except he did not have his house's support, with most Coman supoorting his younger half-brother Korey. Both sought for the Highlord to confirm them. When the Host marched on the Cataracts, Demoth was temporarily made lord, but during the Battle of the Cataracts, Torisen witnessed both men, and decided to confirm Korey.
The Coman have traditionally been very strong allies of the Caineron, with lots of interbreeding between the two houses. However, their new lord, Korey, is less of an ally that previous lords have been, and so this bond is faltering.
The Coman have have a been at odds with the Edirr, being houses of similar size and neighbors right across the river. The Edirr sometimes poach on the Coman's side of the river, with the Lords Edirr sometimes leading the raids themselves, just for the devilment of it in it's own right.
↑To Ride a Rathorn, "Chapter VII: In the Bear's Den", I — "Then the Coman, small and shrill, like their house;"
↑ 2.02.12.2Dark of the Moon, "Chapter 2: The Hell Hunt" — "Lord Coman of Kraggen Keep had recently died without designating a successor. It was customary in such instances as this for the oldest son to become the new head of the household. […] But he had his doubts about Demoth's ability to command. So, apparently, did most of the elders of Demoth's own family, who supported a younger son named Korey. Unfortunately, Korey's mother was a Caineron, and to give that family any more influence could prove fatal to the Highlord's own power."
↑Dark of the Moon, "Chapter 10: The Lurking Past" — " 'He fired the hollow, against my express orders!' 'And he sent Kendar down into the mist to fight. Three times. […] Over a hundred, and as many killed on the slopes,' Korey said angrily. […] Torisen had turned to Demoth. 'I was wrong, and your kinsmen were right: You aren't fit to lead.' "
↑Seeker's Mask, "Part I", I — "she herself was a Coman with two Caineron grandmothers."
↑To Ride a Rathorn, "Chapter I: An Unfortunate Arrival", II — "the former Lord Coman had been a staunch Caineron ally, but the new one, Korey, was wavering. Caldane was said to be furious about that,"
↑Bound in Blood, "Chapter V: Fractures", III — "It didn't matter that the Coman and Edirr were neighbors often at odds, though not in this class."
↑The Sea of Time, "Chapter II: A Willow Rampant" — " 'The Coman complain about the Edirr poaching on their side of the river. Sweet Trinity, can’t they manage their own territory?' Marc cleared his throat. 'It’s a bit more serious than that. I hear that sometimes one of the Lords Edirr leads a raid himself, for the sheer devilment of it.' Torisen looked up sharply. 'That’s dangerous. If Essien or Essiar should meet with an accident on Coman land, there’ll be Perimal to pay.' "