Final answer:
The characters in Giovanni Boccaccio's The Decameron fled from Florence due to the Black Death, seeking refuge in a villa where they shared stories covering various life themes.
Step-by-step explanation:
The city that the characters in Giovanni Boccaccio's The Decameron fled from because of the plague was Florence. In this literary work, a group of individuals sought refuge from the Black Death by isolating themselves in a villa outside the city. As they passed the time, they exchanged stories that dealt with themes such as love, mortality, and fortune.
The Decameron gives insight into not only the individual reactions to the plague but also the broader social responses it engendered during the pandemic.