The First Blight was the first of four instances where an Arch-Demon led the Darkspawn armies against Thedas. It started when mages of the Tevinter Imperium attempted to overthrow the Maker. Instead, they tainted the Golden City and became the first of the Darkspawn. They kidnapped females of other species and turned them into the Broodmothers. These creatures spawned new types of Darkspawn and soon, there were thousands of the creatures. They unearthed an Old God and tainted it, turning it into an Arch-Demon.
The Darkspawn swept across Thedas, destroying the kingdoms of the Dwarves. Then, they turned to the other races and begin to destroy them too. The situation seemed hopeless until the Grey Wardens were created. Their ability to resist the taint of the Darkspawn gave them an edge in battle and within several decades, the Arch-Demon was slain and the Darkspawn were driven to the Deep Roads.