The famous Roman general known for his military campaigns against the Gauls was Julius Caesar. He played a vital role in the expansion of the Roman Republic through his conquests, particularly documented in his work "Commentarii de Bello Gallico." Caesar's military genius led to the decisive victories that resulted in the Roman annexation of vast territories in Gaul (modern-day France and Belgium). His campaigns not only brought wealth and slaves to Rome but also significantly raised his political profile, contributing to his eventual rise to power as a dictator. His actions, however, also stirred political tensions leading to his assassination in 44 BCE.