Because most of the people who knew how to write in the early Middle Ages were monks, most of them wrote about serious things like God and Heaven and Hell. Even writers who weren't monks, like Dante, usually wrote about Christian ideas. But Boccaccio was different. Boccaccio wrote about real people and their real lives. Some of his stories are love stories, some of them are horror stories or ghost stories, and some are funny, but all of them are the kinds of things that might happen to real people. He wasn't at all interested in Christian issues.
Boccaccio was born in Florence, Italy, in 1313 AD. His father was not married to his mother, but Boccaccio grew up with his father and his stepmother. His father was a rich banker in Florence, so Boccaccio was able to have a tutor, who may have had him read Dante's Inferno.
When Boccaccio was about fourteen his father's bank sent him to Naples, in southern Italy, to work for their bank branch there. Boccaccio moved to Naples (then controlled by Robert the Wise) with his father, and he became an apprentice at the bank, learning how to be a banker himself. But Boccaccio didn't like banking, and by the time he was twenty he convinced his father to let him study law instead.
Giovanni Boccaccio (ca. 1365)
Law school let Boccaccio meet many interesting writers and scholars, so that even though he never got to be much of a lawyer, he did become a great writer. Like Dante, Boccaccio wrote in Italian and not Latin. He never learned to read Greek, but he did read Roman writers like Ovid, Tacitus, Martial, and Cicero. In 1341, when he was 28 years old, Boccaccio and his father moved back to Florence, where they lived most of the rest of their lives.
When Boccaccio was thirty-five, many people in Florence caught the plague, and three-quarters of the population (three out of every four people in Florence) died of the plague. Among them were many of Boccaccio's friends and his step-mother. Nobody knows for sure whether Boccaccio was just lucky to survive the plague, or if he left town during it. After the plague, Boccaccio was able to meet another Italian writer, Petrarch, and the two of them became good friends.
Boccaccio's most famous work is the Decameron, which is a lot of short stories strung together. There are a hundred tales in the Decameron, which Boccaccio published in 1371, when Boccaccio was 58 years old. Almost all of these stories came from earlier collections of stories, mostly from further east, like the Indian Jataka tales, the Arabian Nights, and the Shahnameh, which were available in Latin translations at the new medieval universities.
By this time Boccaccio had gotten very fat, and because of this he was sick all the time and had trouble with his heart. But he kept writing: in 1374, he published a collection of short biographies of famous women, the first book of its kind. The biographies started with Eve in the Garden of Eden, moved through Agrippina and Irene, and included women of his own time like Joanna of Naples. Boccaccio died in Florence the next year, at 62, in 1375 AD.