At the Battle of the Teutoburg Forest, over a period of 3 days, an alliance of Germanic tribes wore down and eventually annihilated 3 Roman legions (about 16,000 to 20,000 men). The Romans attempted several defensive night tactics. On the first night they managed to erect a fortified camp. On the second night, they marched at night in an attempt to break through the encircling Germanic forces, but the Germans had already built a wall in their way, and when combat resumed the following day, the Romans were defeated.