The Great Plague was the last big outbreak of bubonic plague in London. It started in April 1665, and continued into 1666, spread by fleas which were carried by rats. It's hard to be certain how many people died (you can find out why below), but the Great Plague probably killed a quarter of Londoners, as well as a lot of people in many other towns and villages around England.
Bubonic plague is not a nice way to die. You catch it from being bitten by a flea, and the disease spreads around your body through your lymphatic system (which is part of your immune system, so it should be fighting disease not spreading it). Large lumps called buboes swell up in your armpits, neck or groin. They ooze pus and blood as they break open. Black spots appear on other parts of your body. Your nose, lips and the tips of your fingers may turn black as the flesh dies. You get a fever and vomit blood. In a week or less, you are likely to be dead.
Plague had been a problem in England for over 300 years, ever since the Black Death of 1348, which was the first big outbreak of bubonic plague in England, and actually much worse than the Great Plague. The Black Death was probably the same disease as the Great Plague, and killed up to half of the population of England.
Over the next three centuries, there were many more outbreaks of plague, including several serious ones in London in the 1600s. When the first cases of plague were reported in April 1665 - only three deaths that month, in fact - the government recognised that this might become a big outbreak, and started shutting up households where cases were confirmed.
Acral gangrene, caused by bubonic plague. The flesh on this person's fingertips has died.
This household quarantine, as it was called, is one of the big reasons that we don't know for certain how many people died in the Great Plague. At that time, there were no registry offices, so you didn't go and report deaths at an official place. Instead, people called 'searchers' found out from the churches and gravediggers who had died, and then went to ask the family about the cause of death.
If you didn't go to church - for example, if your family was Jewish or Catholic - the searchers might not know about you at all, so you wouldn't be included in their numbers. But even if they found out and came to your house to ask how your brother or sister had died, your family might choose to lie.
The family had to pay the searcher one groat to record the cause of the person's death. This wasn't much money - perhaps equivalent to about £1.50 today. If the cause of death was plague, the house would be shut up with the family inside. Imagine being a prisoner in your own home, waiting to see if you were going to die too, while you watched your brothers, sisters, and parents die! This is what happened to Lucy's family, and five of them died. It's not hard to see why families might chose to pay the searcher two groats instead of one, and offer them a cup of ale, in exchange for writing down a different cause of death.
Official numbers report almost 70,000 deaths from the Great Plague, but estimates put the true number closer to 100,000. In the months of July, August and September 1665, thousands of people were dying every week, and the churchyards couldn't fit any more graves in. Burial pits were dug instead, and carts drove through the streets to collect the bodies, their drivers shouting "Bring out your dead". As more people died, there were too many bodies and not enough carts, and bodies began to be piled up outside houses. There are records of one plague pit still being dug at one end while the carts tipped the bodies in at the other end. Many plague pits became heaps of rotting bodies, and as Joe notices in the summer of 1666, the smell from the churchyards was still horrifying almost a year after the plague started to die down.
One very famous story about the Great Plague is the story of Eyam, a village in Derbyshire which chose to cut itself off after cloth from London brought fleas or rats with it carrying the disease. The villagers of Eyam made a great sacrifice in isolating themselves from everyone in the surrounding countryside. About 80% of them died, but they stopped the plague from spreading. There are several fantastic novels based on this story, including Children of Winter by Berlie Doherty, and A Parcel of Patterns by Jill Paton Walsh, which made a huge impression on me when I was a teenager.