In September 52 BCE, the Roman proconsul Gaius Julius Caesar and his army besieged and forced the surrender of an army of some eighty thousand Gauls led by the Arvernian aristocrat Vercingetorix at Alesia (Mount Auxois in the Côte-d'Or, France). Was that battle Caesar's greatest victory and a decisive moment in world history? Does Caesar deserve to be rated among history's greatest generals, a match for Alexander? In Caesar's Greatest Victory, independent scholars John Sadler and Rosie Serdiville answer in the affirmative.

Caesar claimed divine descent from the goddess Venus and the Roman King Ancus Marcius. He was an excellent orator and writer—Cicero said that every prudent author steered clear of subjects Caesar had written about. His life was scandalous and his political career unprecedented. Cato the Younger called him the only sober man who tried to wreck the constitution. After conquering Gaul, Caesar became dictator perpetuus and shortly thereafter a god, following history's most notorious assassination on the Ides of March 44 BCE. But was he also a great military commander?

Chapter 1 "An Ancient City in Gaul," is an assessment of Caesar's writings as a source for his own campaigns in Gaul. Sadler and Serdiville rightly stress that the intended audience of his Commentaries was likely more interested in stirring deeds of glory than endless topographical details, and Caesar gave it what it wanted. The authors then provide a brief preview of Caesar's Gallic command (58–52 BCE) and discuss the debate about the site of the battle of Alesia, ultimately siding with those who argue for Mount Auxois, whose topography best fits Caesar's description of both the battle site and associated military actions (9, 11).

Chapter 2, "De Rei Militarii" [sic; read De Re Militari], supplies a useful introduction to Roman military history. Making effective use of Vegetius's fourth-century CE Epitome of Military Science, the authors discuss the evolution of the legionary army, its tactical organization, recruitment, training, and ranks, as well as kits and weaponry, logistics, and encamping. They conclude that the legionary soldiers, "the distillation of half a millennium of experience and adaptation, … empowered Caesar to conquer Gaul and allowed him, despite the difficulties and reverses of the 52 BC campaign, to finally get the better of Vercingetorix and bring him to bay and corral him in Alesia" (36).

Chapter 3 and 4, "Way of the Gaul" and "Way of the Warrior," concern Gallic society and warfare. Noting that the Gauls/Celts at the time of Alesia lived in an oral society, the authors caution that we are forced to view their culture, including settlement patterns and religion, solely from Caesar's emphatically Roman perspective. Building on relevant archaeological and anthropological studies,[1] they highlight the diversity of Gallic civilization. The Gauls, Celts, or Galatians differed linguistically and in their customs and social organizations. Nevertheless, they also shared certain traits. Gallic society had a segmentary structure in which kinship relations played a crucial role, and, as at Rome, clientage permeated Gallic relationships, politics, culture, and art (52). But other characteristics made it difficult for the Gauls to effectively resist Caesar and his well-trained, veteran troops. In particular, their public assemblies or councils were often afflicted with divided leadership (59), which translated into problems of command on the battlefield. Although Gallic warriors fought bravely, they lacked the command and control structures and sheer staying power to withstand the highly disciplined Roman legions (73).

Chapters 5–8, respectively, "De Bello Gallico—The Gallic Wars 58–52 BC," "Total War 52 BC," "Tightening the Vice," and "The Relief and Final Battle," tell the story of Caesar's command in Gaul in more detail. The authors rightly stress Caesar's titanic ambition and the overtly imperialist motives for the Roman presence in Gaul. They also explain how domestic political pressures compelled Caesar to succeed in Gaul or be destroyed by his enemies in Rome.

We learn in chapter 5 that, at the end of a revolt instigated by the Treveri and Eburones in 54–53 BCE, Caesar executed the Senonian aristocrat Acco. This act convinced many Gauls that the Romans were "here to stay" (97). Believing Caesar would be distracted by events in Rome, several tribes rebelled. After the Carnutes massacred Romans at Cenabum (Orléans), Vercingetorix took control of the rebellion. In response, Caesar crossed through the pass of the Cevennes in deep snow and attacked the Arverni, forcing the surrender of Vellaundunum and recapturing Cenabum. Crossing the Loire, he took Noviodunum and besieged Avaricum (Bourges), the main town of the Bituriges. Committed to a scorched earth war policy, Vercingetorix refused to fully defend Avaricum. Caesar's capture of the town confirmed the wisdom of the rebel leader's Fabian tactics.

After sending his legate Labienus north to deal with the Senones and Parisi, Caesar moved again against the Arverni (in the Auvergne). He tracked them to their stronghold of Gergovia (La Roche-Blanche), but was forced to retreat when the doubtful loyalty of his Aeduan allies threatened his supply lines. This triggered the revolt of the Aeduans and most other Gallic and Belgic tribes. Caesar reacted by rejoining Labienus and concentrating a force of some forty thousand legionaries, as well as units of German cavalry and light infantry.

Caesar next invaded the territory of the Sequani to shield his province of Transalpine Gaul against the threat posed by Vercingetorix and his reinforced Gallic army. After an ill-advised cavalry attack on Caesar's marching legionaries at Mont Reux, Vercingetorix retreated with his eighty thousand infantry and twelve thousand cavalry (Caesar's numbers) to Alesia, a hill town of the Mandubii.

Caesar and his ten to twelve legions and allied mercenaries[2] constructed an eleven-mile-long circumvallation around the hill. Its features are described here in great detail. They included eighty-foot towers along the rampart wall and ironically named antipersonnel devices—lilia (lilies), stimuli (prods), cippi (posts), tribuli (thorns)—positioned in front of the ditches. An even longer (13-mile) concentric contravallation was built to defend against an attack of the relief army Caesar knew would come. Military historians will find the whole detailed description of these siege works (128–36) highly instructive.

After Caesar's Germanic cavalry repelled a raid by Vercingetorix's cavalry from within the besieged town, the anticipated Gallic relief army of 240,000 (!) infantry and 8,000 cavalry (Caesar's inflated numbers again) showed up. Its night attack on the besiegers was defeated thanks to the leadership of Caesar's adjutants Marc Antony and Gaius Trebonius. The battle was then settled when the Gallic relief force, attempting to take a beleaguered Roman camp built on "disadvantageous" ground, was driven off by Caesar, whose sudden appearance in the thick of the fighting (wearing his signature red cloak) inspired the Roman cavalry and infantry. Vercingetorix could not break out of Alesia and the relief army could not break in. Caesar's red cloak notwithstanding, Roman legionaries won the battle of Alesia as much with their shovels and pickaxes as with their swords and spears.

Vercingetorix surrendered to Caesar the next day. Although the rebellion continued for another year, the battle of Alesia was decisive. Vercingetorix remained a prisoner for six years, walked in Caesar's triumphal procession through the streets of Rome, and was ritually strangled to death. For the next five hundred years, all Gaul remained a central part of the Roman imperium.

The last chapter, "Legacy," sketches Caesar's career after Alesia and addresses philosophical questions about the morality of his campaigns in Gaul and the use of history and archaeology to further modern nationalist agendas. The French, for their part, have woven the story of a heroic Celtic defeat and a Roman victory into a nationalist narrative of unity. Caesar's original intervention in Gaul was arguably a just war (bellum iustum) but, after 57 BCE, he was pursuing an opportunistic mission of self-aggrandizement. The authors convincingly argue that Alesia was Caesar's greatest battle and a decisive moment in world history, as a decentralized society was torn apart and rearranged. Out of the defeat at Alesia was born the possibility of a unified Gallic nation—France.

Caesar was certainly Rome's greatest commander: his military strengths were those of Rome itself: scrupulous preparation, organization, discipline, courage, and resolution. To claim that he was the equal of Alexander (165), however, is unjustified. Both men were vain: Caesar liked his frilly sleeves and red cloak, Alexander his white-plumed helmet. But Caesar was forty-eight years old when he conquered Gaul; Alexander had overthrown the entire Persian empire by the age of thirty. At Alesia, Caesar showed a mastery of positional warfare and rallied his faltering troops. Alexander took Tyre and Gaza after long sieges and personally led his cavalry into battle at the set-piece battles of Granicus, Issus, and Gaugamela. For Caesar, war was a means to end. For Alexander, war was the end in itself. Caesar laid the foundations of a unified Gaul, Alexander made possible the Hellenistic world. Indeed, Caesar himself understood that he was no Alexander.[3]

Such arguable comparisons aside, John Sadler and Rosie Serdiville have produced an informative, well-written, and entertaining account of one of history's decisive battles and its charismatic protagonist. They manage to put their readers on the battlefield with Caesar in a succinct narrative enlivened with acute historical analogies.