The rapid spread of the bubonic plague throughout Europe in the 14th century was primarily caused by trade routes that facilitated the movement of infected fleas and rats. The plague, transmitted via fleas on rats, spread along trade paths from Asia into Europe, notably through the Silk Road and maritime routes. Unsanitary living conditions, poor public health measures, and limited medical knowledge exacerbated the situation. As a result, the pandemic decimated the population, leading to profound social, economic, and cultural changes, reshaping European society and influencing future public health policies.