Plague is a deadly infectious disease that is caused by a bacterium that can be spread in the air, by direct contact, from bites of fleas, or by contaminated undercooked food or materials. The symptoms of plague vary. In the case of the Black Death of 1348 or the Plague of London in 1665, it was bubonic plague, where places all over the body swelled up and turned black. It is treatable nowadays, like so many other infections, but in the case of the Black Death it killed between a third and a half of the people of Europe.

The Black Death began in China and spread with merchants along the Silk Road through Asia to Europe and Africa. Some people have guessed that is caused the world's population of the time to fall from 450 million to between 350 million. The worst affected was China, which lost half of its population, while the average in Europe was a third of its population lost, down from about 75 million to about 50 million.

The Great Plague (1665–66) was the last major outbreak of the bubonic plague in Britain. Since the Black Death, plague had reoccurred from time to time in Europe with it breaking out in different places every twenty years or so. In other parts of Europe it continued to 1750.

The great Plague was an event that affected much of Britain, although it is often thought of as affecting just London. It certainly killed more people in London than elsewhere, perhaps 100,000, or 15% of London's population, transmitted through the bite of an infected rat flea. Even so, the 1664–66 epidemic was on a far smaller scale than the earlier Black Death.

You will find an account of how the Plague affected the small village of Eyam, in Derbyshire, in the video.