The Stormlands are the areas between King's Landing and the Sea of Dorne. In the east they are bordered by Shipbreaker Bay and the Dornish Sea to the south. Before Aegon's conquest they were ruled by the Storm Kings, and afterwards by House Baratheon, bastard relatives to the Targaryens. The Dornish Marches are located within this region, having been conquered by the Storm Kings, and are ruled by house Caron and lesser marcher lords. The marches were common battlegrounds between the Stormlands, the Reach and Dorne until the last century, when Dorne joined the Seven Kingdoms. Bastards born in the Stormlands are given the surname Storm.
Storm's End is the seat of House Baratheon and, before them, the ancestral seat of the Storm Kings extending back many thousands of years. According to legend, the first Storm King in the age of the First Men was Durran, who won the love of Elenei, the daughter of the sea god and the goddess of the wind. He took her as wife, and in a rage her parents sent vast storms to shatter his keep and kill his wedding guests and family. Durran declared war against the gods and raised several castles over Shipbreaker Bay, each larger and more formidable than the last. Finally, the seventh castle stayed in place and resisted the storms. Some believe this is because the Children of the Forest took a hand in its construction; others believe that a young boy who grew up to be Brandon Stark, the builder of the Wall, advised Durran on its construction. The truth of the matter is unknown.
Storm's End is exceptionally formidable. In the history of Seven Kingdoms, it has never fallen to either siege or storm. Its outer defences consist of a huge curtain wall, 100 feet (30 m) tall and 40 feet (12 m) thick on its thinnest side, nearly 80 feet (24 m) thick on its seaward side. The wall consists of a double course of stones with an inner core of sand and rubble. The wall is smooth and curving, the stones so well placed that there are nearly no places where the wind can get into cracks between the stones. On the seaward side, there is a 150-foot (46 m) drop below the wall into the sea.
The castle itself consists of one huge drum tower crowned with formidable battlements, so that from a distance enemies can see what appears to be a single huge, spiked fist thrusting towards the sky in defiance. The tower is so large that it can comfortably contain stables, barracks, armoury and lord's chambers all in the same structure.
Storm's End is said to be protected by spells woven into the very walls that prevent the use of any magic against it.
Although never taken in battle, Storm's End has endured several sieges and battles in recent history. The last Storm King, Argilac the Arrogant, abandoned his impressive defences to meet Orrys Baratheon in open battle during Aegon Targaryen's War of Conquest, and suffered accordingly. During the War of the Usurper, Storm's End was besieged for a year by the host of Lord Mace Tyrell, who commanded the landward forces, whilst Paxter Redwyne's fleet of the Arbor kept the castle cut off by sea. Stannis Baratheon, commanding the defence, refused to yield and his men were reduced to eating rats. A smuggler named Davos Seaworth ran the blockade to resupply the castle and Stannis rewarded him by knighting him, but took several of his fingers as compensation for his smuggling. After the war, Stannis was furious when his brother Robert, now king, gave the castle to their younger brother Renly and placed Stannis in command of cold, windswept Dragonstone, which led to many years of bitterness on Stannis' part. During the War of the Five Kings the castle supported Renly and was besieged by Stannis. Following Renly's death, the castle castellan refused to yield. He was killed under mysterious circumstances after the red priestess Melisandre was smuggled under the castle. Soon after this, the castle surrendered to Stannis's forces. Later in the war, the castle was besieged by a strong army under Mace Tyrell, but he only had the castle under siege for a few weeks before he abandoned the siege to return to King's Landing after the arrest of his daughter Margaery by the High Septon for immoral behaviour. The castle remains loyal to King Stannis Baratheon.