House Greenstone
Who would want Greenstone? Was there a battle?". - The Winds of Winter
House Greenstone of Greenstone is the ruling First Man house of the Estermont Isles. Their seat is Greenstone, a dank and dismal green land.

Their banners depict four green rocks stacked on top of each other on teal. Their words are "Leaf and Stone".
History
The Greenstones have lived on the coldest and outermost isles in southern Westeros since men walked the Arm of Dorne. Lashed by thunder and assailed by deadlier tides and tidal waves than anywhere else, the lords of Estermont are a solitary lot, finding some respite from the storms in the weirwood groves dotted about the island chain where they spend hours in contemplation.
Millennia ago they discovered beautiful luscious greenstones on the shores of Estermont that gave them their name, and with them forged necklaces, rings, weapons, and even a crown at one point. But most outside think they are named for the dismal moss-coloured rocks and mountains that make up the Greenstone's realm - an unwelcoming, cold place few people want to go.
Houses Sworn to House Greenstone
- House Tudbury of Tudbury Hall