In October 1347, Genoese trading ships docked in Messina, Sicily, carrying sailors already dying of an unknown disease — bodies covered in black boils oozing blood and pus. Port authorities ordered the ships out of harbour, but it was too late.
The Black Death — primarily caused by the bacterium *Yersinia pestis*, spread by fleas on rats — swept across Europe over the next five years, killing an estimated 30–50% of the continent's population. Approximately 25 million Europeans died, making it the deadliest pandemic in recorded human history.
The catastrophe disrupted feudal economies, accelerated the decline of serfdom (labourers could now demand better wages), shook the Church's authority, and left a profound cultural mark: the *danse macabre* tradition, the flagellant movement, and widespread Jewish persecution as scapegoating. Europe's population did not recover to pre-plague levels for over 200 years.