The Conquest of Gaul tells the story of the Roman Conquest of what is now France, Switzerland, most of the Low Countries, and parts of present day Germany. It was written by Julius Caesar, the Governor of the Roman province of Transalpine Gaul from 59 B.C. until he was declared Dictator of Rome in 44 B.C. He presents a linear account of the conquest of Gaul set forth as a series of books, each book covering one year of his governorship. The first seven books were written by Caesar himself as yearly reports to Rome. The seventh book covering 51 B.C. was written after Caesar’s death by Aulus Hirtius who had served with him in Gaul.   “The Conquest of Gaul†is a revealing look at the manner in which Rome, the most powerful nation of its time conducted military operations. Caesar is perfectly placed to describe the operations in Gaul as he personally commanded the operations he describes.
Book I is the story of the first year of Caesar’s governorship of Gaul 58 B.C. it details the methods he used to defeat the Helvetii. They were a Gallic tribe attempting to migrate into Gaul from the vicinity of present day Switzerland. Caesar attempted to stop their migration through diplomacy but they continued their march into Gaul. Caesar recounts the campaign in which he pursued and defeated them ultimately expelling them from Gaul. The book also describes his campaign against Ariovistus a German chieftain who had subjugated some native Gallic tribes. In his narrative Caesar describes Roman siege methods for the first time. Caesar succeeds in expelling Ariovistus from Gaul and the book ends with Romans taking up winter quarters in Gaul and Caesar returning to northern Italy. Caesar makes pains to stress that he uses violence as a last resort preferring instead to negotiate with the barbarians before setting the Roman legions loose on them. This is somewhat disingenuous as the tone of his writing is such that it is clear he desires to defeat them in battle rather than with words.
Book II carries the tale of the conquest of Gaul into the next year 57 B.C. During the winter rumors reached Caesar of a coalition of Belgic tribes gathering to oppose the Roman invasion of Gaul. Caesar quickly raised two new legions from his province in Italy and marched into Gaul to confront the impending revolt. He faced down a Gallic army at the town of Bibrax and the Belgae melted away to their tribal areas. Caesar then relates the methods he used in chasing and subduing the Belgae throughout the rest of the campaigning season. The legions are put into winter quarters most in the territory of the defeated tribes but three in different tribal areas to forestall rebellion there. Caesar then returned to Italy and notes that fifteen days of celebration ordered at Rome in commemoration of his victories. This book elaborates on Caesar’s skill as a commander both strategically and tactically. It also brings us the first mention of his legions by name particularly the Xth Legion which is to prove one of Caesar’s favorites.
Book III picks up the narrative at the end of 57 B.C. by describing the abortive alpine campaign of Servius Galba in which one Legion and some cavalry are repulsed from opening a trade route through the Alps for the Romans. Caesar next moves into 56 B.C. to detail the campaigns against the tribes along the Atlantic coast who rebelled in response to Roman food requisitions. This rebellion rapidly became almost general and caused Caesar to build a fleet in order to properly subdue the Veneti who lived in seaside cliff fortresses. After subduing the Veneti the Romans under Publius Crassus proceeded to assault and conquer Aquitania where the tribes were also in rebellion. While this was going on Caesar attempts to subdue the Morini and Menapii but is unable to finish the campaign because of the onset of winter. After putting down the revolt the legions were quartered in the rebellious territories for the winter.
Book IV presents the story of the one of Caesar’s greatest feats as a military campaign. In 55 B.C. in response to raids by the Germanic Suebi from across the Rhine who had invaded Gaul and massacred two tribes Caesar invaded Germany. After fruitless negotiations Caesar pursued and trapped the Suebi at the junction of the Moselle and Rhine rivers where he defeated them. To solidify his victory and demonstrate Roman power Caesar decided to cross the Rhine and raid German territory; to do this he had a bridge constructed across the Rhine and took his legions across. They laid waste to the German countryside and returned to Gaul tearing the bridge down after them. To conclude this very active year of campaigning Caesar next invaded Britain even though it was late in the year. He fought several battles before the natives sued for peace promising tribute. Caesar then returned to Gaul where he wintered his legions in Belgic territory.
Book V continues the story into 54 B.C. where Caesar once again faced rebellion in Gaul. Showing how redoubtable the Roman soldier was he started the campaigning season by returning to Britain where he compelled the Britons to pay tribute and surrender hostages before returning to Gaul. On his arrival he learned that one of his legions had been slaughtered by the Eubrones and all Gaul was in revolt. Caesar immediately marched to the relief of another of his legions that was under siege. He broke the siege and continued into northern Gaul to quell the rebellion. The rebellion ended when the leader of the revolt Indutiomarus was caught and killed by the Romans.
Book VI covers the year 53 B.C. which once again saw almost ceaseless campaigning by Caesar. He called up additional legions from Rome and his province and immediately set out to defeat the Treverii who remained in revolt. After defeating them he proceeded to re-cross the Rhine to punish the German tribes who had the revolt. As before he bridged the Rhine and proceeded to lay waste to the crops and villages of the Germans. At the end of the year he retired across the Rhine and settled the legions in winter quarters in the territory of the Treverii to ensure their submission.
Book VII tells the story of the greatest threat Caesar was to face in his time in Gaul, the revolt of Vercingetorix in 52 B.C. which would culminate with one the greatest sieges of the ancient world. The Gauls hearing word of troubles in Rome and seeing their chance, rose in revolt thinking the Romans would be distracted and unable to counter them. When Caesar heard of the revolt hastened back to Gaul from Italy and mobilized his legions to put down the rebellion. Caesar first laid siege to and captured the town of Avaricum then pursued Vercingetorix to Gergovia where the Romans suffered a partial defeat before withdrawing. After refitting his troops Caesar pursued the Gauls to Alesia where he laid siege to Vercingetorix. While this was in progress an army approached to relieve the Gauls in Alesia causing Caesar to construct both inward and out ward facing siege lines. Facing starvation the Gauls attempted to break the siege but was decisively defeated with Vercingetorix being captured. After the siege all the tribes of Gaul quickly made peace with the Romans. Caesar put his legions into winter quarters and returned to northern Italy.
Book VIII is the only book not written by Caesar it tells of the events of 51 and 50 B.C. in which Caesar put down the final revolt by the Gauls and then defies the Roman Senate by bringing troops to Rome thus threatening civil war. In 51 B.C. the Gauls rose once more and Caesar rapidly put the rebellion down defeating Gallic armies of Bituriges, Carnutes, and the Bellovaci with customary swiftness. Caesar then proceeded to the town of Uxellodunum which he laid siege to and captured. In order to forestall further revolt he decided to make an example of the defenders releasing them only after cutting off the hands of the soldiers so that all could see the cost of rebellion. Then Hirtius describes the actions that led up the civil war but goes no farther.
Caesar’s Commentaries are perhaps the best source extant for Roman military methods being written by the commander of the armies involved. There are numerous examples of the Roman’s superiority in arms and strategy. Caesar makes plain that there were some very hard fought battles but through superior discipline and morale the Romans always s managed to succeed. He mentions the importance of logistics to his success many times, emphasizing that it was always at the back of his mind. The Romans were masters of military engineering which he does not fail to point out. He describes in detail the methods of both how the Rhine was bridged as well as how the siege-lines in Alesia were constructed. This book should be required reading for anyone studying ancient history military or otherwise. It provides a detailed glimpse of one of the most important periods in ancient history written by one of the pivotal figures of a pivotal time.