On this day, November the 1st, in the year of 1348, the Bubonic Plague (also known as the Black Death), a plague which caused the death of at least 25 million Europeans, is believed to have reached Great Britain’s largest city, London (On This Day).

The plague, known for causing buboes (swollen lymph nodes that are painful and can burst after a certain amount of build up), was caused by rats with the disease from Asia spreading to Europe (Britannica).