Greenstone is the seat of House Estermont on the island of Estermont in the Stormlands.
King Robert Baratheon, Queen Cersei Lannister and some of the court, including Ser Jaime Lannister, spent a fortnight at Greenstone. Robert cheated on Cersei with a cousin of his and Cersei believes that it was there that she and Jaime conceived Joffrey Baratheon. Jaime gave the castle the nickname "Greenshit".
A Dance with Dragons
A force of the Golden Company under the command of Marq Mandrake takes over Greenstone.
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