In the spring of 58 Caesar took up his duties as governor of Cisalpine and Narbonese Gaul—i.e., northern Italy and southern France. In 71 Ariovistus had led 15,000 Germans into Gaul at the request of one Gallic tribe seeking assistance against another. He had provided the desired aid and then had remained to establish his rule over all the tribes of northeastern Gaul. One of these, the Aedui, appealed to Rome for help against the Germans (61); the Senate authorized the Roman governor of Narbonese Gaul to comply, but almost at the same time it listed Ariovistus among rulers friendly to Rome. Meanwhile 120,000 Germans crossed the Rhine, settled in Flanders, and so strengthened Ariovistus that he treated the native population as subject peoples and dreamed of conquering all Gaul.14 At the same time the Helvetii, centering about Geneva, began migrating westward, 368,000 strong, and Caesar was warned that they planned to cross his province of Narbonese Gaul on their way to southwestern France. “From the sources of the Rhine to the Atlantic Ocean,” says Mommsen, “the German tribes were in motion; the whole line of the Rhine was threatened by them; it was a movement like that when the Alemanni and the Franks threw themselves upon the falling empire of the Caesars . . . five hundred years afterward.”15 While Rome plotted against him, Caesar plotted to save Rome.
At his own expense, and without the authority he should have sought from the Senate, he raised and equipped four extra legions besides the four already provided him. He sent a peremptory invitation to Ariovistus to come and discuss the situation; as he had expected, Ariovistus refused. Deputations came now to Caesar from many Gallic tribes, asking for his protection. Caesar declared war against both Ariovistus and the Helvetii, marched northward, and met the Helvetian avalanche in a bloody battle at Bibracte, capital of the Aedui, near the modern Autun. Caesar’s legions won, but by a narrow margin; in these matters we must for the most part follow his own account. The Helvetii offered to return to their Swiss homeland; Caesar agreed to give them safe passage, but on condition that their territory should accept the rule of Rome. All Gaul now sent him thanks for its deliverance, and begged his aid in expelling Ariovistus. He met the Germans near Ostheim,II and slew or captured (he tells us) nearly all of them (58). Ariovistus escaped, but died soon afterward.
Caesar took it for granted that his liberation of Gaul was also a conquest of it: he began at once to reorganize it under Roman authority, with the excuse that in no other way could it be protected against Germany. Some Gauls, unconvinced, rebelled, and invoked the aid of the Belgae, a powerful tribe of Germans and Celts inhabiting north Gaul between the Seine and the Rhine. Caesar defeated their army on the banks of the Aisne; then, with a celerity of movement that never allowed his foes to unite, he moved in succession against the Suessiones, Ambiani, Nervii, and Aduatici, conquered them, despoiled them, and sold the captives to the slave merchants of Italy. Somewhat prematurely he announced the conquest of Gaul; the Senate proclaimed it a Roman province (56), and the common people of Rome, as imperialistic as any general, shouted the praises of their distant champion. Caesar recrossed the Alps into Cisalpine Gaul, busied himself with its internal administration, replenished his legions, and invited Pompey and Crassus to meet him at Luca to plan a united defense against the conservative reaction.
To forestall Domitius they agreed that Pompey and Crassus should run against him for the consulate for 55 B.C..; that Pompey should be made governor of Spain, and Crassus of Syria, for five years (54-50); that Caesar should be continued for another five years (53-49) as governor of Gaul; and that at the end of this term he should be allowed to seek a second consulate. He furnished his colleagues and friends, from the booty of Gaul, with funds to finance their campaigns; he sent great sums to Rome to provide work for the unemployed, commissions for his supporters, and prestige for himself, by an extensive program of public buildings; and he so oiled the palms of the senators who came to sample his loot that the movement to repeal his laws collapsed. Pompey and Crassus were elected consuls after the usual bribery, and Caesar returned to the task of persuading the Gauls that peace is sweeter than freedom.
Trouble was brewing on the Rhine below Cologne. Two German tribes had crossed into Belgic Gaul as far as Liége, and the nationalist party in Gaul was seeking their help against the Romans. Caesar met the invaders near Xanten (55), drove them back to the Rhine, and slew such of them—women and children as well as men—as were not drowned in the river. His engineers then built in ten days a bridge over the great stream, there 1400 feet wide; Caesar’s legions crossed, and fought long enough on German soil to establish the Rhine as a secure frontier. After two weeks he retraced his steps into Gaul.
We do not know why he now invaded Britain. Possibly he was lured by rumors that gold or pearls abounded there; or he wished to capture the tin and iron deposits of Britain for Roman exportation; or he resented the aid that Britons had sent to the Gauls, and thought that Roman power in Gaul must be made secure in every direction. He led a small force across the Channel at its narrowest point, defeated the unprepared Britons, took a few notes, and returned (55). A year later he crossed again, overcame the British under Cassivelaunus, reached the Thames, exacted promise of tribute, and sailed back to Gaul.
Perhaps he had heard that revolt was once more agitating the Gallic tribes. He suppressed the Eburones and marched again into Germany (53). Returning, he left his main army in northern Gaul, while with his remaining troops he went to winter in north Italy, hoping to devote a few months to mending his fences in Rome. But early in 52 word came to him that Vercingetorix, the ablest of the Gallic chieftains, had united nearly all the tribes in a war for independence. Caesar’s situation was precarious in the extreme. Most of his legions were in the north, and the country between them and himself was in rebel hands. He led a small detachment over the snow-covered Cevennes against Auvergne; when Vercingetorix brought up his forces to defend it, Caesar left Decimus Brutus in command and, with a few horsemen, rode in disguise across all Gaul from south to north, rejoined his main army, and at once led them to the attack. He besieged, captured, and sacked Avaricum (Bourges) and Cenabum (Orléans), massacred their populations, and replenished his depleted supplies with their treasuries. He moved on to assail Gergovia; there, however, the Gauls resisted so resolutely that he was compelled to withdraw. The Aedui, whom he had rescued from the Germans, and who heretofore had remained his allies, now deserted him, captured his base and stores at Soissons, and prepared to drive him back into Narbonese Gaul.
It was the lowest ebb of Caesar’s fortunes, and for a time he considered himself lost. He staked everything upon a siege of Alesia (Alise Ste.-Reine), where Vercingetorix had gathered 30,000 troops. Caesar had hardly distributed a like number of soldiers around the city when word came that 250,000 Gauls were marching down upon him from the north. He ordered his men to raise two concentric walls of earth around the city, one before them, the other behind them. Against these walls and the desperate Romans the armies of Vercingetorix and his allies threw themselves in repeated vain attacks. After a week the army of relief broke up in disorder for lack of discipline and supplies, and melted into ineffectual bands at the very moment when the Romans had reached the end of their stores. Soon thereafter the starving city sent Vercingetorix at his own suggestion as a prisoner to Caesar, and then surrendered to the Roman’s mercy (52). The town was spared, but all its soldiers were given to the legionaries as slaves. Vercingetorix was led in chains to Rome; there he later graced Caesar’s triumph and paid with his life for his devotion to liberty.
The siege of Alesia decided the fate of Gaul and the character of French civilization. It added to the Roman Empire a country twice the size of Italy and opened the purses and markets of 5,000,000 people to Roman trade. It saved Italy and the Mediterranean world for four centuries from barbarian invasion; and it lifted Caesar from the verge of ruin to a new height of reputation, wealth, and power. After another year of sporadic revolts, which the angry general put down with uncharacteristic severity, all Gaul accepted subjection to Rome. Once his victory was certain Caesar became again the generous conqueror; he treated the tribes with such lenience that in all the ensuing Civil War, when he and Rome would have been helpless to retaliate, they made no move to throw off the yoke. For three hundred years Gaul remained a Roman province, prospered under the Roman peace, learned and transformed the Latin language, and became the channel through which the culture of classic antiquity passed into northern Europe. Doubtless neither Caesar nor his contemporaries foresaw the immense consequences of his bloody triumph. He thought he had saved Italy, won a province, and forged an army; he did not suspect that he was the creator of French civilization.
Rome, which had known Caesar only as a spendthrift, rake, politician, and reformer, was amazed to find him also a tireless administrator and a resourceful general. At the same time it discovered in him a major historian. In the midst of his campaigns, disturbed by the attacks upon him in Rome, he had recorded and defended his conquest of Gaul in Commentaries whose military conciseness and artful simplicity raised them, despite a thousand milia passuum, from a partisan pamphlet to a high place in Latin literature. Even Cicero, shifting again, sang a paean in his praise, and anticipated the verdict of history:
It is not the ramparts of the Alps, nor the foaming and flooding Rhine, but the arms and generalship of Caesar which I account our true shield and barrier against the invasion of the Gauls and the barbarous tribes of Germany. It is to him we owe it that, should the mountains be leveled with the plain and the rivers be dried up, we should still hold our Italy fortified not by nature’s bulwarks but by the exploits and victories of Caesar.16
To which should be added the tribute of a great German:
That there is a bridge connecting the past glory of Hellas and Rome with the prouder fabric of modern history, that western Europe is Romanic, and Germanic Europe classic … all this is the work of Caesar; and while the creation of his great predecessor in the East has been almost wholly reduced to ruin by the tempests of the Middle Ages, the structure of Caesar has outlasted those thousands of years which have changed religions and states.17