The art of keeping ourselves entertained while quarantined dates back many centuries. In 1349, following a bubonic plague epidemic that killed more than half the population of his native Florence, Giovanni Boccaccio (1313–1375) wrote The Decameron — a bingeworthy collection of tales told by seven women and three men who've fled the city and confined themselves in an empty villa in the countryside. With time on their hands, they decide that, every evening, each of them will tell a story touching on a pre-established theme. Taking one day off a week for chores, and of course skipping the Sabbath, they tell one hundred stories about knights and ladies, tricksters and reprobates, star-crossed lovers, and randy monks and nuns.
Each of the ten storytellers, collectively called the Brigata (Italian for “brigade”), has his or her own personality. There is the beautiful, modest Neifile; the fiery, self-possessed Fiammetta, thought to be based on a woman Boccaccio was in love with; the witty, forthright, often transgressive Dioneo, thought to be a surrogate for Boccaccio himself. It is only Dioneo who's allowed to diverge from the themes that govern the stories of any given evening — themes set by the person selected to be that evening's King or Queen.
Thus, when Neifile is Queen, “discourse is had of the fortune of such as have painfully acquired some much-coveted thing, or, having lost, have recovered it”, and Dineo takes it as an opportunity to tell the raunchiest tale in the Decameron. It's so raunchy, J. M. Rigg (who penned the 1903 English translation featured above, widely considered the most complete of the many public domain attempts) elected not to translate it, leaving the dirtiest bits in Italian.
To put it very briefly into English: a beautiful young woman named Alibech who wishes to become a Christian hermit goes wandering through the Tunisian desert, trying to get a monk to show her the ropes. Fearing, however, that they'll be “ensnared by the Devil” if they accept her as a pupil, all the monks tell her there is another holy man “not far from here who is much better able to teach thee that of which thou art in quest than I am”. This goes on until she comes to a young monk named Rustico, who has no such compunctions. He contrives to have them both strip naked, and when “the resurrection of the flesh” occurs a few inches below his abdomen, he tells Alibech this is the Devil, who will torment him until he is put back in Hell. “Now I certainly see that those worthy men... were telling the truth about how sweet a thing it is to serve God”, Alibech tells Rustico a few days later (with thanks to Wayne A. Rebhorn's modern translation,
Such is the sort of entertainment one can expect to find in Boccaccio's always-lively tales from plague-time. Which isn't to suggest Boccaccio shirked mention of the plague itself. It is discussed in several of the stories and, at greatest length, in the introduction, written in the author's own voice:
In Florence, despite all that human wisdom and forethought could devise to avert it, as the cleansing of the city from many impurities by officials appointed for the purpose, the refusal of entrance to all sick folk, and the adoption of many precautions for the preservation of health; despite also humble supplications addressed to God, and often repeated both in public procession and otherwise, by the devout; towards the beginning of the spring of the said year  the doleful effects of the pestilence began to be horribly apparent by symptoms that shewed as if miraculous.
Whether Boccaccio himself was a witness to the 1349 epidemic in Florence is still debated among scholars. By 1349, he may already have been in Ravenna. But in any event he'd certainly seen the horrors of the Black Death: the sudden deaths, the disappearance of whole families, the endless burials often performed without ceremony (for a “dead man was then of no more account than a dead goat would be to-day”).
The Brigata would have been escaping exactly this sort of daily horror, though you might not know it from the lovely series of miniatures that adorn an edition of the book held by the National Library of the Netherlands, depicting them from the moment they meet at the Church of Santa Maria Novella through the telling of their various stories in villa-bound self-isolation. Still, it’s no wonder the stories they favored were so bawdy — and the rules they established for telling them so complicated — trying as they were to take their minds off the uncontrollable devastation nearby.
Boccaccio's stories themselves were drawn from many sources, ranging from classical Greek and Latin to local gossip, from the myths of India to those of the Middle East — and would inspire many other stories in turn. Geoffrey Chaucer borrowed heavily from it in The Canterbury Tales, as did Shakespeare and Keats. Its stories have also inspired many visual artists over the centuries, perhaps most notably Sandro Botticelli who in his series The Story of Nastagio degli Onesti illustrates events from the eighth story of the fifth day. More recently, it has fired the imaginations of the novelist Kathryn Davis, whose The Silk Road (2019) puts a sci-fi twist on the frame story, and the filmmaker Jeff Baena, whose The Little Hours (2017) is loosely based on the first and third stories of the third day. All good reading, and good watching, for our own uncertain, self-isolated times.