It came as quite a surprise to discover how little there is available about the life of peasants from the Carolingian period (CE 750–887). When authors of secondary historical sources discuss the lives of common peasants of the Medieval period, they generally confined themselves to the feudal system of the High and Late Middle Ages (1001–1500). What is even more frustrating is that many histories of the Early Middle Ages (475-1000) claim feudalism arose after the fall of the Roman Empire. However, most aspects of classical feudalism, including hereditary fiefs, multiple layers of vassalage, oaths of fealty, heraldic devices, and all the codes of chivalry, were not yet present until the eleventh century. Manorialism during the Carolingian period was a system based on self-sufficient manors, or estates, which were worked primarily by slaves and surrounded by farms rented or owned by free peasants.