Codex text
When the Antaam invaded the South, the people there were completely unprepared. Antiva and northern Rivain were overrun quickly, with the invaders pushing down through the Green Dales to the Minanter River, leaving only the southernmost of the Free Marches spared. From there, the Antaam pushed west, overpowering Tevinter magic with gaatlok cannons and brute strength until the defenders finally held at Vyrantium. Nevarra was spared, likely due to the Antaam fears of necromancy and unwillingness to attack until Tevinter was conquered, but almost half of northern Thedas fell to Antaam rule in just a few years.
To those asking why the Antaam waited centuries to attack in force if they were this powerful, I would remind them that the Qun teaches that outsiders are to be converted and educated. Under Qunari control, the Antaam have been fighting only Tevinter, and even then, they followed rules governing how and when to attack. Gaatlok cannons were not to be used on civilian targets, for example. When the Antaam broke from the Qun, they threw off the restraints that had held them back.
It is also important to note that the Antaam fought alone. With little in the way of supply lines or experts in food production—the craftspeople and strategic experts who would normally support them had not broken from the Qun when the Antaam did—the invaders needed to attack to keep eating. When they encountered resistance that would have forced a siege, the Antaam invasion stalled. The kithshoks who wished only to conquer now had to learn to rule the lands they would claim.
—Excerpt from Marloqun: The Loss of Reason by Seer Rowan of Dairsmuid