Explain how the Black Death spread, its demographic impact, and how it accelerated the decline of feudalism and serfdom.
In 1347, ships fleeing a siege at a Black Sea trading post arrived in Messina, Sicily, carrying more than cargo: fleas infected with the bacterium that causes bubonic plague, later called the Black Death. Riding the same trade routes that had connected Europe to Asia for centuries (the very Silk Road network from week 5), the disease spread with terrifying speed. Within about four years, it killed an estimated one-third to one-half of Europe's entire population -- a death toll on a scale most of history has never seen.
Such a massive population loss changed medieval society in ways that decades of ordinary events could not have. With so many fewer laborers alive, surviving peasants could demand higher wages and better treatment, since lords desperately needed workers to farm their land -- a huge crack in the foundation of feudalism and serfdom. England even passed a law, the Statute of Labourers (1351), trying to freeze wages at pre-plague levels, but it mostly failed, and resentment over such laws helped fuel the Peasants' Revolt of 1381. Fear and grief also led to tragic scapegoating: some communities blamed and violently persecuted Jewish residents for the plague, despite no truth to the accusation. Historians view the Black Death as a turning point that, alongside other pressures, helped push medieval Europe toward the end of serfdom and, eventually, toward the changes of the Renaissance.
Mastery looks like: They can explain how the Black Death spread, its rough death toll, and at least one specific way it weakened feudalism and serfdom.
Common stumbles: Treating the Black Death as only a medical event without tracing its major social and economic effects on feudalism.