Attempting to secure the borders of the empire upon the rivers Danube and Elbe, Augustus ordered the invasions of Illyria, Moesia, and Pannonia (south of the Danube), and Germania (west of the Elbe). At first everything went as planned, but then disaster struck. The Illyrian tribes revolted and had to be crushed, and three full legions under the command of Publius Quinctilius Varus were ambushed and destroyed at the Battle of the Teutoburg Forest in AD 9 by Germanic tribes led by Arminius.