House Casterly ( Casterly )
House Casterly of Casterly Rock is the extinct house of the First Men that ruled the Westerlands until the arrival of the Andal adventurers.
According to legend, Lann the Clever tricked them out of Casterly Rock with no weapons but his wits. Thus, House Casterly was extinguished and Lann started the line of the Lannisters, which would rule the Rock from then on.
There is no information regarding House Casterly’s banner or motto, nor any member of the house has been referred to by name.