In the history of Europe, the Middle Ages or medieval period (also spelt mediaeval or mediæval) lasted from approximately 500 to 1500 AD. It is the second of the three traditional divisions of Western history: antiquity, medieval, and modern. Major developments include the economic predominance of agriculture, exploitation of the peasantry, slow inter-regional communication, the importance of personal relationships in power structures, and the weakness of state administration. The period is sometimes subdivided into the Early, High, and Late Middle Ages, and the early medieval period is alternatively referred to as the Dark Ages.

Population decline, counterurbanisation, the collapse of centralised authority, the mass migration of tribes (mainly Germanic peoples), and Christianisation, which had begun in late antiquity, continued into the Early Middle Ages. The movement of peoples led to the disintegration of the Western Roman Empire and the rise of new kingdoms. In the post-Roman world, taxation declined, the army was financed through land grants, and the blending of Later Roman civilisation and the invaders' traditions is well documented. The Eastern Roman Empire (or Byzantine Empire) survived, but lost the Middle East and North Africa to Muslim conquerors in the 7th century. Although the Carolingian dynasty of the Franks reunited many of the Western Roman lands by the early 9th century, the Carolingian Empire quickly fell apart into competing kingdoms which later fragmented into autonomous duchies and lordships.

During the High Middle Ages, which began after 1000, the population of Europe increased greatly as the Medieval Warm Period allowed crop yields to increase, and technological and agricultural innovations introduced a "commercial revolution". Slavery nearly disappeared, and peasants could improve their status by colonising faraway regions in return for economic and legal concessions.