Celtic warfare
The "Gallic Wars" were a series of military campaigns waged by the Roman proconsul Julius Caesar against Gallic tribes, lasting from 58 BC to 51 BC. The Romans would also raid Britannia and Germania, but these expeditions never developed into full-scale invasions. The Gallic Wars culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul. The wars paved the way for Caesar to become the sole ruler of the Roman Republic.
Campaign history of the Roman military
During a term as praetor in Iberia, Pompey's contemporary Julius Caesar of the Roman Julii clan defeated the Calaici and Lusitani in battle. Following a consular term, he was then appointed to a five-year term as Proconsular Governor of Transalpine Gaul (current southern France) and Illyria (the coast of Dalmatia). Not content with an idle governorship, Caesar strove to find reason to invade Gaul, which would give him the dramatic military success he sought. To this end he stirred up popular nightmares of the first sack of Rome by the Gauls and the more recent spectre of the Cimbri and Teutones. When the Helvetii and Tigurini tribes began to migrate on a route that would take them near (not into) the Roman province of Transalpine Gaul, Caesar had the barely sufficient excuse he needed for his Gallic Wars, fought between 58 BC and 49 BC. After slaughtering the Helvetii tribe, Caesar prosecuted a "long, bitter and costly" campaign against other tribes across the breadth of Gaul, many of whom had fought alongside Rome against their common enemy the Helvetii, and annexed their territory to that of Rome. Although "fierce and able" the Gauls were handicapped by internal disunity and fell in a series of battles over the course of a decade.