The Middle Ages is commonly dated to the period of time from the fall of the Western Roman Empire (in the 5th century) until what is referred to as the Early Modern Period (beginning in the 16th century). The origin of the term "Middle Ages" come from Italian Renaissance humanists in the 15th century. Humanists believed that culture had stagnated, owing to the loss of many classical Latin texts, since the fall of Rome in the 5th century.

The Roman empire reached the height of its territorial extent during the second century. In the following two centuries this began to slowly decline. In 285 the Roman Emperor Diocletian divided the Empire into two halves: the western Roman empire, governed from Ravenna, was subordinate to the wealthier east. In 330 Constantine refounded the city of Byzantium and renamed it Constantinople proclaiming it the new capital.

The dwindling financial resources of the empire led to the empire's problem of defense in which the finances and armies were spread too thin. After the Battle of Adrianople in 378 the Roman army was destroyed leaving the west undefended.

Following this, the Volkerwanderung ("wandering of the peoples") began taking place (approx. AD 300-700). This period marked the transition from Late Antiquity to the Early Middle Ages. Tribes from norther Europe began moving in and settling in what was the Western Roman empire; such include the Huns, Bulgars, Avars and Magyars, along with a large number of Germanic and later Slavic peoples. Some of these tribes were welcomed by the Roman senate or emperor. Others conducted small scale military invasions to gather plunder. One such invasion was the sack of Rome by the Visigoths in 410.

Roman institutions crumbled drastically by the end of the 5th century and in 476 Romulus Augustulus was deposed by the Barbarian king Odacer. Byzantine emmperors maintained claim over the west, but attempts to reassert control failed. The west was ruled primarily by kings who received support of barbarian armies.

Between the 5th and 8th centuries new peoples and powerful leaders filled the political void left by Roman government. Germanic tribes established regional hegemonies within the boundaries of the former Roman empire. Such of these hegmonies include the Ostrogoths in Italy, the Visigoths in Hispania, the Franks and Burgundians in Gaul and western Germany, the Angles and the Saxons in Britain, and the Vandals in North Africa. This effected the social and economial states of the fallen Roman state. Conditions of trade and manufacture became unsafe. Major industries that depended on long-distance trade, such as large scale pottery manufacture, vanished almost overnight.

The migration movement is generally divided into two phases, the first of which lasted from about AD 300 to 500. The Visigoths were the first to formally enter Roman territory in 376 as refugees from the Huns. The Romans tolerated them with the agreement that they defend the Danube frontier. They eventually rebelled, invaded Italy and finally Rome itself in 410. They then settled in Iberia where they founded a kingdom that was to last 300 years.

During the second phase of the migration period Slavic tribes settled in Central and Easter Europe, primarily in easter Magna Germania. The Bulgars conquered the eastern Balkan territory of the Byzantine Empire in the seventh century. The Lombards, a Germanic people, settled in northern Italy, the region now known as Lombardy.

The Arabs attempted to invade Europe through Asia Minor but were defeated at the siege of Constantinople by the joint forces of Byzantium and Bulgaria in 717-18. Simultaniously, they invaded Europe through Gibraltar, conquering Hispania (the Iberian Peninsula) wresting it from the Visigoths in 711. They were finally defeated by the Franks at the Battle of Tours in 732. These battles established the boundaries between Christendom and Islamics for the next three centuries.

In Gaul, the Franks, a fusion of western Germanic tribes whose leaders had been strongly aligned with Rome, entered Roman lands more gradually and peacefully during the 5th century. They were generally accepted as rulers by the Roman-Gaulish population. They defended the territory from advances ob the Allemanni, Burgundians and Visigoths.