"This article is written from the point of view of the 'Garion' universe"
The House of Cthan was a noble faction of Murgos who governed the Cthan Military District of Cthol Murgos. As with the other Murgo houses, they will have ruled as Kings of Cthol Murgos at one point as well.
Princess Prala, betrothed of King Urgit was of the House of Cthan. She carried the sword of King Ad Rak Cthoros, who led the Murgos at the Battle of Vo Mimbre, implying that he was also of the House of Cthan.