That field, however, established his military fame, and paved the way for his subsequent usurpations. The conquests of Caesar in Western Europe are unique in the history of war, and furnish no parallel. Other conquests may have been equally brilliant and more imposing, but none were ever more difficult and arduous, requiring greater perseverance, energy, promptness, and fertility of resources. The splendid successes of Lucullus and Pompey in Asia resembled those of Alexander. We see military discipline and bravery triumphing over the force of multitudes, and a few thousand men routing vast armies of enervated or undisciplined mercenaries. Such were the conquests of the English in India. They make a great impression, but the fortunes of an empire are decided by a single battle. It was not so with the conflicts of Caesar in Gaul. He had to fight with successive waves of barbarians, inured to danger, adventurous and hardy, holding life in little estimation, willing to die in battle, intrepid in soul, and bent on ultimate victory. He had to fight in hostile territories, unacquainted with the face of the country, at a great distance from the base of his supplies, exposed to perpetual perils, and surrounded with unknown difficulties. And these were appreciated by his warlike countrymen, who gave him the credit he deserved. The ten years he spent in Gaul were the years of his truest glory, and the most momentous in their consequences on the future civilization of the world, since it was not worn-out monarchies he added to the empire, but a new territory, inhabited by brave and simple races, who were to learn the arts and laws and literature of Rome, and supply the government with powerful aid in the decline of its strength. It was the conquered barbarians who, henceforth, were to furnish Rome with soldiers, and even scholars and statesmen and generals. Among them the old civilization was to take root, among them new states were to arise on which the Romans could impress their own remarkable characteristics. It was the western provinces of the empire that alone were vital with energy and strength, and which were destined to perpetuate the spirit of Roman institutions. The eastern provinces never lost the impress of the Greek mind and manners. They remained Greek even when subdued by the imperial legions. Syria, Asia Minor, Egypt, were filled with Grecian cities, and Asiatic customs were modified by Grecian civilization. The West was purely Roman, and the Latin language, laws, and arts were continued, in a modified form, through the whole period of the Middle Ages. Even Christianity had a different influence in the West from what it had in the East. In other words, the West was completely Latinized, while the East remained Grecian. Though the East was governed by Roman proconsuls, they could not change the Graeco-Asiatic character of its institutions and manners; but the barbarians were willing to learn new lessons from their Roman masters.