Harrenhal was constructed before the Conquest by King Harren the Black, ruler of the Iron Islands and the Riverlands. The dangerously proud Harren created Harrenhal to be the greatest of all castles, larger and stronger than any other stronghold. Unfortunately, the high walls and forbidding towers of Harren’s stronghold were useless against the dragons of House Targaryen; Aegon and his sisters burned Harren and his host alive within the castle’s walls. Due to the extreme heat, the castle took on a charred, melted appearance leaving the castle to serve as a monument to the hubris of King Harren.
Harrenhal, which sits on the shore of the lake known as Gods Eye, consists of five massive towers and an equally monstrous curtain wall. Its walls are incredibly thick and its rooms are built on a scale that would be more comfortable for giants than for humans. The castle, however, is next to useless; it is too big to garrison effectively and too expensive to maintain. Because of this crippling weakness, along with a semi-legendary curse left on the stronghold after Harren’s death, no House has been able to hold Harrenhal for long, and its halls have seen countless horrors. A long line of Houses, including the accursed Lothstons and the unfortunate Whents, held the castle prior to the War of the Five Kings.
During the early stages of that war, Lady Whent yielded Harrenhal to Lord Tywin Lannister, who held it himself for a short while before turning it over to Ser Amory Lorch. Although Queen Cersei promised Lord Janos Slynt that he would rule in Harrenhal, then-King’s Hand Tyrion Lannister revoked Slynt’s claim and later granted the castle to Petyr Baelish. Because of the war, however, neither man ever set foot in the castle.
Harrenhal was first held by the Lannister garrison under Lorch, who was assisted by the Brave Companions (also known as the Bloody Mummers), a sellsword company led by Vargo Hoat. But with the aid of a disguised Arya Stark and the Braavosi assassin Jaqen H’ghar, Northern prisoners within the castle revolted and convinced Hoat to change sides. Lord Roose Bolton soon arrived to hold the castle for the north, but quickly departed and left Harrenhal in the hands of Hoat and the Bloody Mummers. Hoat, although he did at one time capture Jaime Lannister, was unable to stop Ser Gregor Clegane from retaking the castle for House Lannister. Clegane savagely executed Hoat, but was called to King’s Landing to participate in the trial by battle of Tyrion Lannister.
After Tyrion escaped and murdered Lord Tywin, Queen Regent Cersei Lannister dispatched Ser Jaime Lannister to take control of the castle. Jaime cleared out the remnants of Clegane’s men and left a garrison consisting mainly of the pious regiment known as the Holy Hundred. Harrenhal’s fate remains uncertain.