The bubonic plague, also known as the Black Death, is believed to have started in Europe and Asia in the mid-14th century. The initial outbreak of the bubonic plague occurred in the years 1347 to 1351. It is thought to have originated in Central Asia or China and spread along trade routes, reaching Europe via the Silk Road and other trading networks. The disease was caused by the bacterium Yersinia pestis, which was transmitted by fleas that infested black rats. The bubonic plague had a devastating impact, causing widespread illness, death, and social upheaval throughout Europe, Asia, and other parts of the world.