In the history of Europe, the Middle Ages or medieval period (also spelt mediæval or mediaeval) lasted approximately from 500 AD to 1500, although alternative starting and end points exist. The Middle Ages is the middle period of the three traditional divisions of Western history: antiquity, medieval, and modern. The medieval period is itself 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, invasion and the mass migration of tribes, which had begun in late antiquity, continued into the Early Middle Ages. The large-scale movements of the Migration Period, including of Germanic peoples, led to the rise of new kingdoms in Western Europe. In the 7th century, the Middle East and North Africa came under caliphal rule with the Arab conquests. The Byzantine Empire survived in the Eastern Mediterranean and advanced secular law through the Code of Justinian. In the West, most kingdoms incorporated extant Roman institutions, while the influence of Christianity expanded across Europe. The Carolingian dynasty of the Franks established the Carolingian Empire during the later 8th and early 9th centuries in Western Europe before it succumbed to internal conflict and external invasions. During the High Middle Ages, which began after 1000, the population of Europe increased greatly as technological and agricultural innovations allowed trade to flourish and the Medieval Warm Period climate change allowed crop yields to increase. Manorialism, the organisation of peasants into villages that owed rent and labour 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 organised in the High Middle Ages. This period also saw the formal division of the Catholic and Orthodox churches, with the East–West Schism of 1054. The Crusades, which began in 1095, were military attempts by Western European Christians to regain control of the Holy Land from Muslims and also contributed to the expansion of Latin Christendom in the Baltic region and the Iberian Peninsula. In the West, intellectual life was marked by scholasticism, a philosophy that emphasised joining faith to reason, and by the founding of universities. The theology of Thomas Aquinas, the paintings of Giotto, the poetry of Dante and Chaucer, the travels of Marco Polo, and the Gothic architecture of cathedrals such as Chartres mark the end of this period. The Late Middle Ages was marked by difficulties and calamities including famine, plague, and war, which significantly diminished the population of Europe; between 1347 and 1350, the Black Death killed about a third of Europeans. Controversy, heresy, and the Western Schism within the Catholic Church paralleled the interstate conflict, civil strife, and peasant revolts that occurred in the kingdoms. Cultural and technological developments transformed European society, concluding the Late Middle Ages and beginning the early modern period. Source: Wikipedia (en)