where allied forces would be awaiting. In his first victory, he eluded the siege of Roman praetor Gaius Vetilius and attracted him to a narrow pass next to the Barbesuda river, where he destroyed his army and killed the praetor. Viriathus's ability to turn chases into ambushes would grant him victories over a number of Roman generals. Another famous Lusitanian ambush was performed by Curius and Apuleius on Roman general Quintus Fabius Maximus Servilianus, who led a numerically superior army complete with war elephants and Numidian cavalry. The ambush allowed Curius and Apuleius to steal Servilianus's loot train, although a tactic error in their retreat led to the Romans retaking the train and putting the Lusitanians to flight. Viriathus later defeated Servilianus with a surprise attack. Possibly the most famous ambush in ancient warfare was that sprung by Germanic warchief Arminius against the Romans at Battle of the Teutoburg Forest. This particular ambush was to affect the course of Western history. The Germanic forces demonstrated several principles needed for a successful ambush. They took cover in difficult forested terrain, allowing the warriors time and space to mass without detection. They had the element of surprise, and this was also aided by the defection of Arminius from Roman ranks prior to the battle. They sprang the attack when the Romans were most vulnerable; when they had left their fortified camp, and were on the march in a pounding rainstorm. The Germans did not dawdle at the hour of decision but attacked quickly, using a massive series of short, rapid, vicious charges against the length of the whole Roman line, with charging units sometimes withdrawing to the forest to regroup while others took their place. The Germans also used blocking obstacles, erecting a trench and earthen wall to hinder Roman movement along the route of the killing zone. The result was mass slaughter of the Romans, and the destruction of three legions. The Germanic victory caused a limit on Roman expansion in the West. Ultimately, it established the Rhine as the boundary of the Roman Empire for the next four hundred years, until the decline of the Roman influence in the West. The Roman Empire made no further concerted attempts to conquer Germania beyond the Rhine. There are many notable examples of ambushes during the Roman-Persian Wars. A year after their victory at Carrhae, the Parthians invaded Syria but were driven back