The expression feudalism' came from the term fief', a type of property holding in which a tenant would hold land from a lord in exchange for service, agricultural or military. By 1300 feudalism in its purest sense was over, and it had evolved into what is known as bastard feudalism'. In the highly hierarchical society of late medieval Europe peasants were at the very bottom. This was the state into which they were born, and very few ever moved socially upwards, which could only be achieved by patronage or education. Peasants were the most affected by the natural disasters of the fourteenth century. Although slavery as it was known in the Ancient Roman Empire had not been a significant feature in society after the Empire's demise, slavery of some sort did survive into the period, but the unfree' peasants cannot be considered in this category.