The Middle Ages form the middle period in a traditional schematic division of European history into three "ages": the classical civilization of Antiquity, the Middle Ages and Modern Times. The idea of such a periodisation is attributed to Flavio Biondo, an Italian Renaissance humanist historian.

The Middle Ages are commonly dated from the fall of the Western Roman Empire (or by some scholars, before that) in the 5th century to the beginning of the Early Modern Period in the 16th century, marked by the rise of nation-states, the division of Christianity in the Reformation, the rise of humanism in the Italian Renaissance, and the beginnings of European overseas expansion which allowed for the Columbian Exchange. There is some variation in the dating of the edges of these periods which is due mainly to differences in specialization and focus of individual scholars. Commonly seen periodization ranges span the years ca. 400–476 AD (the sackings of Rome by the Visigoths to the deposing of Romulus Augustus) to ca. 1453–1517 (the Fall of Constantinople to the Protestant reformation begun with Martin Luther's 95 theses). Dates are approximate, and are based upon nuanced arguments; for other dating schemes and the reasoning behind them, see "periodisation issues", below.

The Middle Ages witnessed the first sustained urbanization of northern and western Europe. Modern European states owe their origins to events unfolding in the Middle Ages; present European political boundaries are, in many regards, the result of the military and dynastic achievements in this tumultuous period.