By the third century, the Roman Empire was overextended. Its military defenses were inadequate to patrol the far-flung borders. The Roman economy also was near collapse. Tied to agriculture, the Romans had never developed commercial expertise. The shortage of liquid capital left industry underdeveloped. The administration of the empire remained similarly crude. With no sense of public credit, the government fell back on unsound monetary policies. The failure to develop a principle of succession also continued to plague the empire.

During the third century, the emperors failed militarily. When the rulers suffered defeat, the legions raised their own commanders to the imperial throne. Successful soldiers, regardless of their social status, could achieve the imperial purple, at least temporarily. These commanders, in turn, passed legislation in favor of the armies in order to maintain their newly won positions. Bribery of the military consisted of increased pay funded by debased coinage. As the quality of coinage declined, prices soared setting off new demands for pay increases and subsequent military revolutions. Most of the soldier/emperors were assassinated. As political instability increased, the empire was subject to more intense assaults from outside its borders, including Berbers in North Africa, Persians in the east and Franks and Allemani in the west.

The imperial administration was unable to deal effectively with widespread barbarian assaults on the borders. Some regional commanders chose to create independent, separatist governments. Political and military instability had devastating effects on the social organization of the empire. As before, a huge gulf arose between the honestiores—soldiers, senators, and those exempt from taxation—and the humiliores—the masses of the population on whom the tax burden of supporting the military fell. Despairing of survival, many men were driven to banditry. Such popular resistance to the imperial administration further disrupted political order.

The attacks on the northern borders of the empire came from various peoples called Germans. Between the second and the fifth century, German political organization changed from typically small bands of kin to powerful tribal confederations. The basic social units of the Germans were households grouped together into related kindred units or clans. Clans were loosely grouped together in tribes. Fragmentation of tribal groups was common because of the feud, carried out against other kinship groups for any offense. Tribal leaders attempted to reduce violence by establishing a system of payments called wergeld in lieu of vengeance. Relationships between different clans were usually typified by raiding and pillaging. Tribal leaders attempted to create group solidarity by religious cults and the comitatus, the society of warriors. The comitatus sometimes served as the basis on which new tribal configurations could be formed. Intertribal violence produced a rough equilibrium of power that prevented the creation of unified Germanic political groups.

Commercial and cultural interaction with the Roman empire destroyed Germanic equilibrium and initiated the development of larger Germanic political units. Comitatus commanders began to serve within the Roman armies and were favored with Roman wealth. Thus the Germanic military organization began to prevail over the original tribal society. The war band leader emerged as the political center around which new and more powerful confederations could coalesce. The increasing organization of Germanic peoples resulted in the Marcomannian Wars at the end of the second century and the confederation of Gothic peoples sufficiently powerful to challenge Roman authority.

The emperors Aurelian and Diocletian temporarily halted the disintegration of the Roman empire.

Diocletian maintained the lofty status of god-emperor, but recognized that the empire was too large for one man to administer. He created the tetrarchy, a division of the empire into four parts ruled by two emperors and two assistants called caesars. The division of the empire into eastern and western halves proved a durable reform. Diocletian also increased the number of provinces and the legions of bureaucrats to staff the new units. He tried to control rampant inflation by issuing new coinage and establishing price and wage controls. In order to shift the economic burden, the emperor imposed a new system of taxation.

The key to his success was his control of the military and his separation of the army from administration. Some of Diocletian’s reforms, though well-intentioned, failed. Attempts to control inflation and to maintain a stable currency fell through. Tax reforms bound tenant farmers (coloni) to their land. Local administration also suffered as the city council members (decurians) were financially ruined. Failure of the Christians to support the cult of the deified emperor led to renewed persecution.

In 305, Diocletian resigned his position in favor of his assistant emperor. Instead of the anticipated orderly succession, a civil war ensued. Constantine, the winner, was the son of one of Diocletian’s caesars. After his victory Constantine granted Christianity the acceptance of the state. Constantine also shifted his capital from Rome to the East. A new center, Constantinople, replaced the old capital as the focus of a Christian empire.

Although Constantine preserved the old public religions during his own lifetime, his successors raised Christianity to the status of state religion. Bishops began to operate as magistrates within the Christian community, and the emperor sought to establish himself as head of Christendom. Constantine called the first great Church council at Nicaea and determined a major doctrinal controversy, the condemnation of Arianism. The acceptance of the state hastened the growth of Christianity within the Roman empire. By the fourth century, the number of Christians rose to thirty million.

The Christian Church of the later Roman empire was well organized under the leadership of the bishops, among whom the Bishop of Rome (the Pope) was the most respected. However, the Church remained divided by significant differences in theological interpretation. Two of the most important issues were the nature of Christ and the means by which salvation could be attained.

The nature of the Trinity—Yahweh, Christ, and the Spirit—was a matter of debate among various Christian communities attempting to accommodate Christianity with the intellectual milieu of the later Roman empire. In particular the relationship between the divinity and humanity of Christ was problematic. Among the extreme positions was that of the Arians which described Christ as entirely a creature and that of the Gnostics which described him as entirely divine. The first Christian theologian to explore the relations within the Trinity fully was Origen of Alexandria. He insisted on the divinity of Christ, but seemed to relegate him to a lesser divinity than the Father. The question of the divinity of Christ had to be adjudicated by Constantine at Nicaea in 325. Controversies continued to rage, even after Nicaea. Arians, who believed that Christ was not equal with the Father, successfully converted the Goths to their cause. Monophysites, who argued that Christ was only divine with no human attributes, gained adherents in Syria and Egypt. A council at Chalcedon in 451 proclaimed that not only did the Trinity consist of three divinities, but also that Christ possessed both a fully human and a fully divine nature. This position was never accepted in regions of the East where Monophysitism continued to flourish. In the western half of the empire, theologians concentrated more on defining the process of salvation. Donatists and Pelagians argued that only a select few capable of practicing more perfect lives could be assured of salvation. Donatists wished to cast out of the Church all those who, in times of persecution, had collaborated with the Roman government. Pelagians taught that humans could resist sin and achieve salvation without Christ’s sacrifice. The primary opponent of these elitist theologies was Augustine, bishop of Hippo in North Africa. In responding to Donatists and Pelagians, Augustine provided a foundation for the Christian’s relationship to God. Augustine posited a “city of God’’ that superseded all earthly governments. One participated in the true “city” through the sacraments. Salvation was a gift of grace granted freely by God to the elect. Thus a distinction was made between the visible Church that existed in the material world and the invisible Church of the elect. Christianity was not dependent on the survival of Rome or Roman culture, for the invisible Church was unaffected by the political storms of the later empire.

Some Christians chose to abandon society entirely in search of a more purely contemplative life. An Egyptian peasant, Anthony (250-355), gave away all his earthly possessions and retreated to the desert where he began to attract other Christians seeking to cut themselves off from the secular world.

Those who chose to abandon the secular world followed two paths: communal organization or solitary life. Communal monastic living first became popular in Egypt. There, communities of Christians dedicated themselves to rigorous prayer and self-mortification under the complete command of abbots who ruled the communities. The fame of these communities as models of Christian living and contemplation spread throughout the Roman empire. The Egyptian monasteries attracted many recruits, including Jerome who founded a monastery in Palestine. There, he translated the Bible into Latin. Basil the Great transferred the Egyptian model of communal living to the Greek-speaking world. Basil was more connected to the secular world of politics than the abbots of Egypt, and the Greek monasteries became the training centers for the non-monastic heads of the Church in the eastern half of the Roman empire. Basil, himself, became bishop of Caesarea. Benedict of Nursia created the most popular model of monasticism in the West. Benedict’s rule enjoined monks to a life of poverty, chastity, and obedience. The rule divided the day into regular intervals of prayer and meditation. Unlike the East, western monks and abbots generally remained aloof from secular politics.

The alternative to communal living was isolation. This practice was most common in the Syrian desert where hermits lived lives of nomadic individualism. These Christian radicals rejected ancient society in entirety. One hermit, Simeon Stylites, supposedly lived for more than thirty years on the top of a pillar. Because the rest of Christian society tended to view the hermits as supermen and women, these spiritual athletes were called upon for advice and as arbitrators of social ills. The tradition of holy hermits was not common in the western half of the empire.

The appearance of the Huns from the East shattered the Gothic confederation on the borders of the Roman empire. The Visigoths, the largest of the Germanic groups, sought refuge in the empire. Relations between the Romans and Germans soon deteriorated. At the battle of Adrianople, the Visigoths defeated and killed the emperor Valens. In the aftermath of their victory, the Visigoths were permitted to reside in the empire under their own government as an independent people. From their original entry point in the eastern half of the empire, the Visigoths migrated under the leadership of their kings to the West. They entered Italy and took Rome in A.D. 410. From Italy they passed on to southern France and Spain.

The armies of the empire were Germanic long before the Visigothic invasion. The Visigoths were simply seen as a new form of Germanic “army” and were supported by the diversion of tax revenues from the regions in which they settled. The Visigothic kings established the kingdom of Toulouse in southern France with imperial consent. Similarly, the Vandals established their kingdom in northern Africa. From this Mediterranean base, the Vandals attacked Roman shipping and Rome itself. With the disintegration of the Hunnic confederacy in 451, the Ostrogoths regained their independence. They entered the eastern half of the Roman empire, but were sent to Italy by the eastern emperor, Zeno. Under the command of their king, Theodoric, the Ostrogoths established a kingdom in Italy. As the last emperor in the West had been set aside in A.D. 476, the Romans regarded Theodoric as the supreme military commander of that half of the empire. The last vestiges of Roman military command were represented by the armies of Flavius Aetius and Syagrius in Gaul. These commanders represented the interests of the local GalloRoman aristocracy. The Franks swept away this last bastion of Romanism. Britain was also abandoned to Germanic invasion. During the fifth century, clans of Germans known as Anglo-Saxons swept the Celtic population of the island to the west and north.

The emperors continued to preserve the fiction that the Germanic kingdoms were Roman armies in the employ of the empire. Provincial elites accepted the barbarians, because they were able to carve out huge estates as autonomous lordships without the interference of the imperial government. In the absence of imperial administration in the western half of the empire, the Christian episcopacy began to function as the local authority. The office of bishop was increasingly identified with the local Gallo-Roman aristocracy.

Unlike the West, the East avoided the process of Germanization. The East fell back on Hellenistic traditions that antedated the Roman empire. Tax structures remained relatively undisturbed, and the barbarians were never able to gain a stranglehold on the military or the administration. Similarly, the Church did not replace the imperial administration.