The Middle Ages or Medieval period is a stretch of European history that lasted from the 5^th until the 15^th centuries. It began with the collapse of the Western Roman Empire, and was followed by the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the traditional division of Western history into Classical, Medieval, and Modern periods. The period is subdivided into the Early Middle Ages, the High Middle Ages, and the Late Middle Ages.

In the Early Middle Ages, depopulation, deurbanization, and barbarian invasions, which began in Late Antiquity, continued. The barbarian invaders formed new kingdoms in the remains of the Western Roman Empire. In the 7^th century North Africa and the Middle East, once part of the Eastern Roman Empire (the Byzantine Empire), became an Islamic Empire after conquest by Muhammad’s successors. Although there were substantial changes in society and political structures, the break with Antiquity was not complete. The still sizeable Byzantine Empire survived and remained a major power. The empire’s law code, the Code of Justinian, was widely admired. In the West, most kingdoms incorporated extant Roman institutions, while monasteries were founded as Christianity expanded in western Europe. The Franks, under the Carolingian dynasty, established an empire covering much of western Europe; the Carolingian Empire endured until the 9^th century, when it succumbed to the pressures of invasion — the Vikings from the north; the Magyars from the east, and the Saracens from the south.

During the High Middle Ages, which began after AD 1000, the population of Europe increased greatly as technological and agricultural innovations allowed trade to flourish and crop yields to increase. Manorialism — the organization of peasants into villages that owed rent and labor services to the nobles; and feudalism — the political structure whereby knights and lower-status nobles owed military service to their overlords, in return for the right to rent from lands and manors – were two of the ways society was organized in the High Middle Ages. The Crusades, first preached in 1095, were military attempts, by western European Christians, to regain control of the Middle Eastern Holy Land from the Muslims. Kings became the heads of centralized nation states, reducing crime and violence but making the ideal of a unified Christendom more distant. Intellectual life was marked by scholasticism, a philosophy which emphasized joining faith to reason, and by the founding of universities. The philosophy of Thomas Aquinas, the paintings of Giotto, the poetry of Dante and Chaucer, the travels of Marco Polo, and the architecture of Gothic cathedrals such as Chartres are among the outstanding achievements of this period.

The Late Middle Ages were marked by difficulties and calamities, such as famine, plague, and war, which much diminished the population of western Europe; in the four years from 1347 through 1350, the Black Death killed approximately a third of the European population. Controversy, heresy, and schism within the Church paralleled the warfare between states, the civil war, and peasant revolts occurring in the kingdoms. Cultural and technological developments transformed European society, concluding the Late Middle Ages and beginning the Early Modern period.