Caesar and Pompey in the Civil Wars

The two generals were essentially inventing entirely new ways to wage war as they went along. The ensuing weeks of siege and skirmishes fought in the no man's land between the two walls has often been compared to the modern trench warfare of World War I rather than a classical era infantry battle. Caesar lost some thousand troops in the fighting, and was forced to abandon his wall and retreat. But what initiative Pompey had shown by attacking was immediately negated by his hesitancy to pursue Caesar's fleeing army.