The catastrophic event that occurred in Europe, killing millions in the 14th century, was the Black Death, also known as the Bubonic Plague. It began in the 1340s and spread rapidly, believed to have been transmitted through fleas on rats and through human contact. This devastating pandemic resulted in the deaths of an estimated 25 to 30 million people, wiping out about one-third of Europe’s population at that time. The socio-economic impact was profound, leading to labor shortages, changes in land use, and even shifts in religious and cultural attitudes as societies struggled to cope with the immense loss.