Fortune can bring about great changes in a situation through very slight forces.
—Julius Caesar, Roman leader and general
The battle that defined Julius Caesar as a great general and future Roman dictator for life was in Gaul, now modern-day France. He faced daunting odds. His army numbered 60,000 legionnaires, but he was deep in enemy territory and a Gallic force of 80,000 was entrenched in the impregnable hilltop fortress of Alesia.
Caesar first had his men build a wall to encircle and isolate the fortress. This wall was 12 feet tall, ran for 11 miles, and had battlements and fortifications at frequent intervals. When he realized that Gallic reinforcements would arrive and attack from behind, Caesar had his men ...