By 1352 the worst of the Black Death was over. But its impact would last for centuries. The disease had disrupted European civilization with the destructiveness and ferocity of a massive and devastating war. Every aspect of society was permanently altered in some way by the onslaught of the disease. Thousands of European towns and villages lay silenced and abandoned. Manors and small farms were in ruins. Crops rotted in the fields. Churches and monasteries were empty; universities and halls of government were shut down. Banks and businesses went bankrupt. Common graves stretched across the countryside. Vultures, crows, rats, and flies feasted on unburied corpses.

This was the world left to the living. As if this were not bad enough, survivors faced one additional problem: widespread hunger. Few livestock had survived the devastation of the foregoing years. In addition, vast crops...