House Qoherys

House Qoherys is an extinct noble house of the Riverlands. Their sigil was a flaming saltire, red and yellow, between 4 white skulls, on black.

Their seat was the castle of Harrenhal, which was granted to them by Aegon the Conqueror as a reward for their service in the War of Conquest. However, the Qoherys eventually became extinct, and the castle was passed on to House Towers

In the books
In the A Song of Ice and Fire novels, House Qoherys' backstory is the same. Like House Targaryen, they were of Valyrian descent.