According to the Roman historian Tacitus

According to the Roman historian Tacitus, the Germans were notorious as heavy drinkers and gamblers.
The war band - comitatus in Latin - had an important bearing on the origin of medieval feudalism, which was based on a similar personal bond between knights (companions) and their feudal lords (chiefs).
In the first, the defendant had to lift a small stone out of a vessel of boiling water; unless his
A basic factor behind Germanic restlessness seems to have been land hunger.
Their numbers were increasing, much of their land was forest and swamp, and their agricultural methods were inefficient.
Barbarian Invasions
The impetus behind the increasing German activity on the frontiers in the late fourth century was the approach of the Huns.
The Vandals pushed their way through Gaul to Spain and, after pressure from the Visigoths, moved on to Africa, the granary of the Empire.

The End of the West Roman Empire
The decline of Roman rule in the West was hastened as a series of incompetent emperors abandoned Rome and sought safety behind the marshes at the northern Italian city of Ravenna.
The leaders of the imperial army, whose ranks were now mainly German, wielded the real power.
In 475 Orestes, the German commander of the troops, forced the Senate to elect his young son Romulus Augustulus ("Little Augustus") as emperor in the West.
In the following year another German commander, Odovacar, slew Orestes.
Seeing no reason for continuing the sham of an imperial line in the west, he deposed Romulus Augustulus and proclaimed himself head of the government.
Theodoric’s Kingdom in Italy
The disintegration of the Hunnic Empire following the death of Attila freed the Ostrogoths to migrate as other tribes were doing.
Under their energetic king, Theodoric (c. 454-526), the Ostrogoths were galvanized into action.
Theodoric accepted a commission from the emperor in the East to reimpose imperial authority over Italy, now in Odovacar’s hands.
In 488 Theodoric led his people into the Italian peninsula, where, after hard fighting, Odovacar sued for peace and was treacherously murdered.
Theodoric then established a strong Ostrogothic kingdom in Italy with its capital at Ravenna.
Because he appreciated the culture he had seen at Constantinople, Theodoric maintained classical culture on a high level.
Following his death without a male heir in 526, civil war broke out in Italy, paving the way for a twenty-year war of reconquest (535-555) by the armies of the East Roman emperor Justinian.
Italy was ravaged from end to end by the fighting, and the classical civilization that Theodoric had carefully preserved was in large part destroyed.
The Problem Of The Fall Of Rome
Pagan writers attributed the sack of Rome to the rejection of their ancient gods.
In The City of God, St. Augustine argued against this charge and put forth the view that history unfolds according to God’s design. Thus Rome’s fall was part of the divine plan - "the necessary and fortunate preparation for the triumph of the heavenly city where man’s destiny was to be attained."
This view was challenged in the eighteenth century by Edward Gibbon,
Author of the famous Decline and Fall of the Roman Empire, who saw Rome’s fall as "the triumph of barbarism and religion."

Not only the Germans, but also the Christian’s had played an important role in undermining the imperial structure: "The clergy successfully preached the doctrines of patience and
Pusillanimity; ... the last remains of the military spirit were buried in the
Cloister." ^2
Modern historians advance a variety of theories to explain why Rome fell. Some explanations have been rooted in psychological theory.
Thus the basic cause has been attributed to a weakening of morale in the face of difficulties, to a "loss of nerve."
Or it has been argued that the ultimate failure of Rome came from its too complete success - the easy acquisition of power and wealth and the importing of ready-made cultures from conquered peoples led to indolence and self-gratification among the ruling classes.
Corrupt high-ranking bureaucrats and military leaders seeking private gain have also been cited as a key factor.
Some historians blame nonhuman causes such as an exhaustion of the soil, drought, malaria, plague, or the presence of toxic amounts of lead in Roman dining pottery and water pipes.
Such single-cause explanations usually reflect a personal bias or axe to grind.
Most historians today attribute Rome’s decline to a combination of interacting forces over a long period of time.
On the political side, no effective system of imperial succession had ever been worked out, and this, plus the failure of the emperors to control the army, resulted in military anarchy, the disintegration of central authority, and the weakening of Rome’s ability to withstand external pressures.
Beginning in the third century, the emperors had to increase the military establishment despite a growing manpower shortage caused by a declining birthrate and by recurrent plagues from Asia (perhaps smallpox or measles).
This decision led to Germanization of the army and to German colonization within the Empire. The West was becoming "barbarized" before the barbarian invasions took place.
The economy of the Empire had been declining for two centuries.
Rome had grown rich on the spoils of conquest.
This source of wealth ended when expansion ceased with the stabilization of the frontiers.
Without manufactures and other sources of new wealth, Rome’s capitalistic economy contracted.
To pay their armies and other costs of government, the emperors continually debased the coinage.
To escape the resulting inflation, the rich invested their wealth in land, which, unlike money, retained its value.
Inflation and a crushing tax burden destroyed much of the middle class.
Eventually, the rigid economic and social reforms of Diocletian and Constantine created a vast bureaucracy that merely aggravated the existing ills in the western half of the Empire, already far along the road to decline.