Serfdom was a common form of legal and socio-economic exclusion in medieval Europe; reconstructing how it operated enhances our understanding of diversity and its significance in the human past. Furthermore, its operation and decline in medieval England feature prominently in four major debates in economic and social history: the causes of the crisis of the early fourteenth century, the role of the Black Death of 1348-9 in triggering fundamental socio-economic change, the role of class struggle in determining particular pathways of economic development, and the origins of capitalism. English serfdom is traditionally portrayed as pervasive and oppressive and, as such, a fundamental cause of the pre-plague crisis and the Peasants' Revolt of 1381. This major survey draws on a vast scholarship and original research to show that, in reality, English serfdom was weak in this crucial period. The reasons for its weakness and the implications for our understanding of economic change are explored. As a result, the Black Death dealt serfdom a mortal blow long before the revolt, as revealed through three case studies documenting its rapid decline on the estate of St Albans abbey, one of England's harshest landowners and a key target in 1381. The book offers insights into the use of theory and evidence in history, and the sizeable gap that could exist between legal norms and actual practice on the ground, and provides the definitive reference point for comparisons with European systems of serfdom.