The historical period known for the spread of the Black Plague in Europe is the 14th century, specifically the years between 1347 and 1351. The Black Death decimated populations across Europe, with estimates suggesting that between 25% to 60% of the population perished. It was caused by the bacterium Yersinia pestis, transmitted through fleas and rodents. The social and economic impacts were profound, leading to labor shortages, increased wages for workers, and a shift in the feudal system. This pandemic significantly altered European society, contributing to changes in public health and a greater focus on science and medicine.