Scotland was divided into a series of kingdoms in the early Middle Ages, i.e. between the end of Roman authority in southern and central Britain from around 400 AD and the rise of the kingdom of Alba in 900 AD. Of these, the four most important to emerge were the Picts, the Gaels of Dál Riata, the Britons of Alt Clut, and the Anglian kingdom of Bernicia. After the arrival of the Vikings in the late 8th century, Scandinavian rulers and colonies were established on the islands and along parts of the coasts. In the 9th century, the House of Alpin combined the lands of the Scots and Picts to form a single kingdom which constituted the basis of the Kingdom of Scotland.

In the history of Europe, the Middle Ages or medieval period lasted approximately from 500 AD to 1500, although some prefer other start and end dates. The Middle Ages is the second of the three traditional divisions of Western history: antiquity, medieval, and modern. Major developments include the predominance of agriculture in the economy, the exploitation of the peasantry, slow interregional communication, the importance of interpersonal relations in power structures, and the fragility of state bureaucracy. The medieval period is itself sometimes subdivided into the Early, High, and Late Middle Ages, and the early medieval period is alternatively referred to as the Dark Ages.