Caesar's Gallic Wars essays chronicle the history of his military engagements during the years 58-51 B.C. in Gaul, Germany, and Britain. And, as an aid to his readers, he provides expository information for those who are unfamiliar with the far-off lands and people encountered during his forays. He opens his book, for example, with a brief description of Gaul, then tells how the Helvetii are first aroused to rebellion by Orgetorix in 61 B.C. and how, after Orgetorix' death, they continue their preparations for war, finally beginning military operations in 58 B.C. Since they plan to march through an area bordering on the Roman Province, Caesar feels that they represent a threat to Roman rule, so he directs his forces against them. And, after defeating the Helvetii, he fights the Germans who have been brought to Gaul by the Sequani tribe. Then, unexplainably, there is a moment of panic within the Roman army, but it manages to regain its courage and crushes the German forces. One of the few to escape, unfortunately, is Ariovistus, a principal German leader.
Book II covers the events of a year later, 57 B.C.; now Caesar battles the Belgae in northern Gaul, and Publius Crassus battles the maritime states on the coast of Gaul. These two operations significantly extend the area of Rome's influence, and the Roman Senate and the populace acknowledge Caesar's achievement by celebrating a thanksgiving of fifteen days.
Book III finds Caesar, during 56 B.C., sending Servius Galba to open a toll-free route through the Alps. But, after this is done, Servius is attacked by the Seduni and Veragri tribes, and after defending himself, finally moves his legion back to safer territory for the rest of the winter. Meanwhile, the Veneti, one of the coastal tribe subdued by Crassus the previous year, begin a rebellion that spreads through the area, so Caesar decides to move against them; his navy wins a major sea battle that ends the rebellion. Other parts of his army, under the direction of Titurius Sabinus and Publius Crassus, defeat the Venelli and their allies under Viridovix, and the tribes of Aquitania. Caesar then subdues the Morini and the Menapii tribes.
Book IV concerns the Usipetes and the Tencteri, two German tribes driven from their homes by the Suebi in 55 B.C. The tribes cross the Rhine in search of new territory, but are defeated finally when Caesar drives them out and moves his own army into Germany for the first time. Then, because some of the Gallic tribes have received military aid from Britain, Caesar decides to make a brief trip across the channel, something no Roman force has done before. He twice defeats the Britons, then returns to Gaul to quell the Morini rebellion and accepts the surrender of the Menapii. Afterward, the Senate decrees a thanksgiving of twenty days; once more, an unprecedented honor.
Book V, chronicling the events of 54 B.C., tells of Caesar's return to Britain with a fleet estimated at 600 ships. He fights his way to the Thames, then moves back to the coast and defeats the British force, commanded by Cassivelaunus. After his return to Gaul, there is a revolt of the Belgae precipitated by Ambiorix and Catuvolcus. Ambiorix successfully tricks and destroys the Roman legion commanded by Sabinus and Cotta. The Nervii attack another Roman camp, but the commander, Cicero, holds them off until Caesar arrives with reinforcements. Labienus defeats a large Gallic force led against him by Indutiomarus, leader of the Treveri.
Book VI, the shortest of the hooks in the Gallic Wars, relates Caesar's adventures during 53 B.C. and also concerns itself with giving us an idea of the different cultures of the Germans and the Gauls. As for the battle narrative itself, it concerns an early revolt of several tribes, quelled by Caesar and Labienus. Also, Caesar again crosses the Rhine, but the Suebi retreat into their forests and he decides against pursuing them and returns to Gaul, where he defeats the rebel Eburones forces under Ambiorix.
Finally, Book VII, the longest in Caesar's narrative, describes how, in 52 B.C., Caesar manages to withstand the revolt of fourteen of the Gallic tribes. Many, of course, do not freely join the rebellion, but are drawn in by political intrigues of various kinds; even the usually faithful Aedui turn against Rome. Caesar's forces take a number of enemy strongholds — Vellaunodunum, Cenabum, Noviodunum, and Avaricum — but they are almost defeated at Gergovia. The Gallic revolt spreads and reaches its greatest dimension under the leadership of vercingetorix, an Arvernian warrior of great power whose father had been chieftain of Gaul. In a major battle at Alesia, the Roman forces defeat Vercingetorix' army and the revolt ends. Rome once more proclaims a thanksgiving of twenty days to honor Caesar for having reconquered Gaul.