Things were less cozy in London. Quarantining was invented during the first wave of bubonic plague in the 14th century, but it was deployed more systematically during the Great Plague. Public servants called searchers ferreted out new cases of plague, and quarantined sick people along with everyone who shared their homes. People called warders painted a red cross on the doors of quarantined homes, alongside a paper notice that read “LORD HAVE MERCY UPON US.” (Yes, the all-caps was mandatory.)

The government supplied food to the housebound. After 40 days, warders painted over the red crosses with white crosses, ordering residents to sterilize their homes with lime. Doctors believed that the bubonic plague was caused by “smells” in the air, so cleaning was always recommended. They had no idea that it was also a good way to get rid of the ticks and fleas that actually spread the contagion.

Of course, not everyone was compliant. Legal documents at the U.K. National Archives show that in April 1665, Charles II ordered severe punishment for a group of people who took the cross and paper off their door “in a riotious manner,” so they could “goe abroad into the street promiscuously, with others.” It’s reminiscent of all those modern Americans who went to the beaches in Florida over spring break, despite what public health experts told them.

Pepys was a believer in science, and he tried to follow the most cutting-edge advice from his doctor friends. This included smoking tobacco as a precautionary measure, because smoke and fire would purify the “bad air.” In June of 1665, as the plague began, Pepys described seeing red crosses on doors for the first time. “It put me into an ill conception of myself and my smell,” he writes, “so that I was forced to buy some roll-tobacco to smell and chaw, which took away the apprehension.”

Quack medicine will always be with us. But there was some good advice, too. During the Great Plague, shopkeepers asked customers to drop their coins in dishes of vinegar to sterilize them, using the 1600s version of hand sanitizer.

Just as some American politicians blame the Chinese for the coronavirus, there were 17th century Brits who blamed the Dutch for spreading the plague. Others blamed Londoners. Mr. Pepys had relocated his family to a country home in Woolwich, and writes in his diary that the locals “are afeard of London, being doubtfull of anything that comes from thence, or that hath lately been there … I was forced to say that I lived wholly at Woolwich.”

By late 1666, the plague had begun its retreat from England, but one disaster led to another. In autumn, the Great Fire of London destroyed the city’s downtown in a weeklong conflagration. The damage was so extensive in part because city officials were slow to respond, having already spent over a year dealing with plague. The fire left 70,000 Londoners homeless and angry, threatening to riot.