Who wrote the Decameron during the Black Death?

Boccaccio, and the frame is the plague itself: ten young Florentines flee the city to a villa in the hills and tell each other a hundred stories over ten days to pass the time. The opening description of Florence in 1348 is one of the primary eyewitness accounts of the epidemic - bodies in the street, families abandoning the sick, the collapse of ordinary obligation.

The stories that follow are almost entirely comic, bawdy and secular - adulterous wives outwitting husbands, corrupt priests, clever servants - and the contrast is the argument. The response to catastrophe is not piety but storytelling and appetite, and the tellers are seven women and three men, with the women given most of the sharpest material.

It went straight into English literature. Chaucer almost certainly knew it, and The Canterbury Tales uses the same device of travellers telling stories in turn; several plots are shared. Boccaccio also wrote in Italian rather than Latin, following Dante, which is part of how Tuscan became the national language - and he spent his later years lecturing publicly on Dante and compiling scholarly works in Latin, having decided the vernacular tales were beneath a serious man.