3. Alesia (52BC)
http://www.youtube.com/watch?v=zMY-BxrCRX4 Before becoming famous for his politicking, Caesar earned his reputation as one of the best commanders in Rome's history. The Roman Republic had all but conquered Gaul by 52BC, so, in one final rebellion against the mighty force, the local tribes united behind Vercingetorix and prepared to meet Caesar's army. Vercingetorix and his 60,000 troops were forced out of Gergovia, leaving them to defend the fortified hilltop town of Alesia. Caesar's immediate thought was to starve the citizens into submission, so he had his troops construct a 12ft high, 11 mile wooden wall around the town. Before the building could be completed, horsemen escaped from the city, which led Caesar to believe they were off to fetch support. In a moment of genius, he ordered his troops to build a second wall around them. The second force, led by Commius and Vercassivellaunos, soon had the second wall surrounded. The relief force and Vercingetorix's army attacked at the same time, with the former attacking a weakened spot in the outer wall. Caesar, realising the defence was almost at breaking point, led 6,000 cavalry outside and attacked the rear of the relief force. The Roman army overran them, and, the next day, Vercingetorix offered to surrender. The siege established Rome's dominance over Gaul and was, arguably, Caesar's greatest victory.