"Instead of the traditional use of spears and swords, we let the Wasteland itself destroy Aegon's army. Almost none survived and Aegon had to call in the help of Lord Orys to defeat King Argilac"
―Trevyr Blackgard
The Great Pass was a major event in the War of Conquest. Aegon the Conqueror wanted to enter the Stormlands and had his men pass through The Borderlands, while he and his sisters rode their dragons through the wasteland. Almost none of Aegon's men survived the dangerous crossing.