Although the Latins dwelled in politically independent towns, their common language and culture produced cooperation in religion, law, and warfare. All Latins could participate in the cults of commonly worshiped divinities, such as the cult of the Penates of Lavinium, Juno of Lanuvium, and Diana (celebrated at both Aricia and Rome). Latins freely intermarried without legal complications. When visiting another Latin town, they could buy, sell, litigate, and even vote with equal freedom. If a Latin took up permanent residence in another Latin community, he became a full citizen of his new home. Although the Latin states occasionally waged war among themselves, in times of common danger they banded together for mutual defense. Each state contributed military forces according to its strength. The command of all forces was entrusted by common assent to a single person from one of the Latin towns. Sometimes the Latins even founded colonies upon hostile territory as military outposts, which became new, independent Latin states, enjoying the same rights as all the other ones. Modern scholars use the term “Latin League” to describe this collection of rights and duties.
According to ancient tradition, Rome’s last three kings not only transformed Rome into a real city but also made it the leader of the Latin League. There is probably exaggeration in this claim. Roman historians were eager to portray early Rome as destined for future greatness and as more powerful than it actually was. Rome certainly became one of the more important states in Latium during the 6th century, but Tibur, Praeneste, and Tusculum were equally important and long remained so. By the terms of the first treaty between Rome and Carthage (509 bc), recorded by the Greek historian Polybius (c. 150 bc), the Romans (or, perhaps more accurately, the Latins generally) claimed a coastal strip 70 miles south of the Tiber River as their sphere of influence not to be encroached upon by the Carthaginians.
Rome’s rapid rise during the 6th century was the achievement of its Etruscan overlords, and the city quickly declined with the collapse of Etruscan power in Campania and Latium about 500 bc. Immediately after the fall of the Roman monarchy, amid Porsenna’s conquest of Rome, his defeat by the Latins, and his subsequent withdrawal, the plain of Latium began to be threatened by surrounding hill tribes (Sabines, Aequi, and Volsci), who experienced overpopulation and tried to acquire more land. Thus Rome’s external affairs during the 5th century largely revolved around its military assistance to the Latin League to hold back these invaders. Many details in Livy’s account of this fighting are, however, unreliable. In order to have a literary theme worthy of Rome’s later greatness, Livy’s annalistic sources had described these conflicts in the most grandiose terms. Yet the armies, military ranks, castrametation (i.e., techniques in making and fortifying encampments), and tactics described belong to the late republic, not the Rome of the 5th century. Roman expansion in Italy
Toward the end of the 5th century, while Rome and the Latins were still defending themselves against the Volsci and the Aequi, the Romans began to expand at the expense of Etruscan states. Rome’s incessant warfare and expansion during the republic has spawned modern debate about the nature of Roman imperialism. Ancient Roman historians, who were often patriotic senators, believed that Rome always waged just wars in self-defense, and they wrote their accounts accordingly, distorting or suppressing facts that did not fit this view. The modern thesis of Roman defensive imperialism, which followed this ancient bias, is now largely discredited. Only the fighting in the 5th century bc and the later wars against the Gauls can clearly be so characterized. Rome’s relentless expansion was more often responsible for provoking its neighbours to fight in self-defense. Roman consuls, who led the legions into battle, often advocated war because victory gained them personal glory. Members of the centuriate assembly, which, as noted above, decided war and peace, may sometimes have voted for war in expectation that it would lead to personal enrichment through seizure and distribution of booty. The evidence concerning Roman expansion during the early republic is poor, but the fact that Rome created 14 new rustic tribes during the years 387–241 bc suggests that population growth could have been a driving force. Furthermore, Romans living on the frontier may have strongly favoured war against restless neighbours, such as the Gauls and the Samnites. The animal husbandry of the latter involved seasonal migrations between summer uplands and winter lowlands, which caused friction between them and settled Roman farmers.
Roman expansion in Italy from 298 to 201 bc.Encyclopædia Britannica, Inc.
Though the Romans did not wage wars for religious ends, they often used religious means to assist their war effort. The fetial priests were used for the solemn official declaration of war. According to fetial law, Rome could enjoy divine favour only if it waged just wars—that is, wars of self-defense. In later practice, this often simply meant that Rome maneuvered other states into declaring war upon it. Then Rome followed with its declaration, acting technically in self-defense. This strategy had the effect of boosting Roman morale and sometimes swaying international public opinion.
Rome’s first major war against an organized state was fought with Fidenae (437–426 bc), a town located just upstream from Rome. After it had been conquered, its land was annexed to Roman territory. Rome next fought a long and difficult war against Veii, an important Etruscan city not far from Fidenae. Later Roman historians portrayed the war as having lasted 10 years (406–396 bc), patterning it after the mythical Trojan War of the Greeks. After its conquest, Veii’s tutelary goddess, Queen Juno, was solemnly summoned to Rome. The city’s territory was annexed, increasing Roman territory by 84 percent and forming four new rustic tribes. During the wars against Fidenae and Veii, Rome increased the number of military tribunes with consular power from three to four and then from four to six. In 406 bc Rome instituted military pay, and in 403 bc it increased the size of its cavalry. The conquest of Veii opened southern Etruria to further Roman expansion. During the next few years, Rome proceeded to found colonies at Nepet and Sutrium and forced the towns of Falerii and Capena to become its allies. Yet, before Roman strength increased further, a marauding Gallic tribe swept down from the Po River valley, raided Etruria, and descended upon Rome. The Romans were defeated in the battle of the Allia River in 390 bc, and the Gauls captured and sacked the city; they departed only after they had received ransom in gold. Henceforth the Romans greatly feared and respected the potential strength of the Gauls. Later Roman historians, however, told patriotic tales about the commanders Marcus Manlius and Marcus Furius Camillus in order to mitigate the humiliation of the defeat.
Roman power had suffered a great reversal, and 40 years of hard fighting in Latium and Etruria were required to restore it fully. The terms of the second treaty between Rome and Carthage (348 bc) show Rome’s sphere of influence to be about the same as it had been at the time of the first treaty in 509, but Rome’s position in Latium was now far stronger. The Samnite Wars