Germania Magna was a wooded and swampy region of Central Europe which was inhabited by the Germanic tribes during the Roman Empire. The Romans under Augustus began to conquer and defeat the peoples of Germania Magna in 12 BC, having Nero Claudius Drusus and Tiberius lead the legions. By 6 AD, all of Germania up to the River Elbe was pacified and occupied by the Romans, with Publius Quinctilius Varus serving as governor. The Roman plan to conquer and incorporate all of Magna Germania was frustrated by the disastrous Battle of the Teutoburg Forest in 9 AD, and Augustus ordered a withdrawal from Magna Germania, complete by 16 AD, establishing the Rhine and the Danube as the Empire's borders. The Roman general Germanicus launched successful punitive expeditions against the Germans from 14 to 16 AD, avenging the defeat at the Teutoburg Forest, but Emperor Tiberius had his legions leave Germania, as the conquest of Germania Magna would require too much effort for little economic gain.