Thus there was no ancient fortification capable of withstanding a long siege when the besieged city was, short of defenders or provisions. With equal forces an attack was generally a failure, for the defenders had always a great advantage. But when the number of defenders was reduced, or when famine pressed, the skill and courage of the assailants would ultimately triumph. Some ancient cities made a most obstinate resistance, like Tarentum; Carthage, which stood a siege of four years; Numantia in Spain, and Jerusalem. When cities were of immense size, population, and resources, like Rome when besieged by Alaric, it was easier to take them by cutting off all ingress and egress, so as to produce famine. Tyre was only taken by Alexander by cutting off the harbor. Babylon could not have been taken by Cyrus by assault, since the walls were three hundred and thirty-seven feet high, according to Herodotus, and the ditch too wide for the use of battering-rams. He resorted to an expedient of which the blinded inhabitants of that doomed city never dreamed, which rendered their impregnable fortifications useless. Nor would the Romans have probably prevailed against Jerusalem had not famine decimated and weakened the people. Fortified cities, though scarcely ever impregnable, were yet more in use in ancient than modern times, and greatly delayed the operations of advancing armies. And it was probably the fortified camp of the Romans, which protected an army against surprises and other misfortunes, which gave such efficacy to the legions.
[Sidenote: The Tribunes.]
[Sidenote: The Centurions.]
[Sidenote: Gradation of ranks.]
The chief officers of the legion were the tribunes, and originally there was one in each legion from the three tribes—the Ramnes, Luceres, and Tities. In the time of Polybius the number in each legion was six. Their authority extended equally over the whole legion; but, to prevent confusion, it was the custom for these military tribunes to divide themselves into three sections of two, and each pair undertook the routine duties for two months out of six. They nominated the centurions, and assigned to each the company to which he belonged. These tribunes, at first, were chosen by the commander-in-chief,—by the kings and consuls; but during the palmy days of the republic, when the patrician power was preeminent, they were elected by the people, that is, the citizens. Later they were named half by the Senate and half by the consuls. No one was eligible to this great office who had not served ten years in the infantry or five in the cavalry. They were distinguished by their dress from the common soldier. Next in rank to the tribunes, who corresponded to the rank of brigadiers and colonels in our times, were the centurions, of whom there were sixty in each legion,—men who were more remarkable for calmness and sagacity than for courage and daring valor; men who would keep their posts at all hazards. It was their duty to drill the soldiers, to inspect arms, clothing, and food, to visit the sentinels, and regulate the conduct of the men. They had the power of inflicting corporal punishment. They were chosen for merit solely, until the later ages of the empire, when their posts were bought, as in the English army. These centurions were of unequal rank,—those of the Triarii before those of the Principes, and those of the Principes before those of the Hastati. The first centurion of the first maniple of the Triarii stood next in rank to the tribunes, and had a seat in the military councils, and his office was very lucrative. To his charge was intrusted the eagle of the legion. [Footnote: Liv. xxv. 5; Caes. B.C., vi. 6.] As the centurion could rise from the ranks, and rose by regular gradation through the different maniples of the Hastati, Principes, and Triarii, there was great inducement held out to the soldiers. In the Roman legion it would seem that there was a regular gradation of rank although there were but few distinct offices. But the gradation was not determined by length of service, but for merit alone, of which the tribunes were the sole judges. Hence the tribune of a Roman legion had more power than that of a modern colonel. As the tribunes named the centurions, so the centurions appointed their lieutenants, who were called sub-centurions.
[Sidenote: Change in the organization of the legions.]
There was a change in the constitution and disposition of the legion after the time of Marius, until the fall of the republic. The legions were thrown open to men of all grades; they were all armed and equipped alike; the lines were reduced to two, with a space between each cohort, of which there were five in each line; the young soldiers were placed in the rear, and not the van; the distinction between Hastati, Principes, and Triarii ceased; the Velites disappeared, their work being done by the foreign mercenaries; the cavalry ceased to be part of the legion, and became a distinct body; and the military was completely severed from the rest of the state. Formerly no one could aspire to office who had not completed ten years of military service, but in the time of Cicero a man could pass through all the great dignities of the state with a very limited experience of military life. Cicero himself served but one campaign.
[Sidenote: Changes under the emperors.]
[Sidenote: Pay of soldiers.]
Under the emperors, there were still other changes. The regular army consisted of legions and supplementa,—the latter being subdivided into the imperial guards and the auxiliary troops. The auxiliaries (Socii) consisted of troops from the states in alliance with Rome, or those compelled to furnish subsidies. The infantry of the allies was generally more numerous than that of the Romans, while the cavalry was three times as numerous. All the auxiliaries were paid by the state; the infantry received the same pay as the Roman infantry, but the cavalry only two thirds of what was paid to the Roman cavalry. The common foot-soldier received in the time of Polybius three and a half asses a day, equal to about six farthings sterling money; the horseman three times as much. The Praetorian cohorts received twice as much as the legionaries. Julius Caesar allowed about six asses a day as the pay of the legionary, and under Augustus the daily pay was raised to ten asses—little more than four pence per day. Domitian raised the stipend still higher. The soldier, however, was fed and clothed by the government.