Dante Alighieri (1265 - 1321) was a Florentine poet, a man often identified with the early Renaissance, yet his greatest work, La Divina Commedia (The Divine Comedy), is a culminating statement of the medieval world view.
Dante was born into a prominent Florentine family with loyalties to the Guelfs, a political alliance involved in complex opposition to the Ghibellines. His own views were independent and fiercely patriotic--taking the Ghibelline side while Guelphs ruled the city, he joined a Guelph army to defeat foreign troops allied with the Ghibellines in 1289. He became one of the ruling council of the city in 1300. But while serving in Rome as a envoy to Pope Boniface VIII in 1302 (to whom he later assigned a particularly unpleasant place in the Inferno), he was declared a criminal by the "Black Guelph" faction that had come to power in Florence.
He lived in exile for many years. As his fame as an artist grew, he was offered the chance to return to the city he loved, on condition of paying a fine. He refused--and, indeed, at his death refused to be buried there. His grave is in Ravenna.
The Divine Comedy describes Dante's journey through Hell (/Inferno), Purgatory (/Purgatorio), and Paradise (/Paradiso), guided first by the Roman epic poet Virgil and then by his beloved Beatrice. While the vision of Hell, the Inferno, is vivid for modern readers, the theological niceties presented in the other books require a certain amount of patience and scholarship to understand.
Dante wrote the Comedy in his regional dialect. By creating a poem of epic structure and philosophic purpose, he established that the Italian language was suitable for the highest sort of expression, and simultaneously established the Tuscan dialect as the standard for Italian.
Other works include /De Vulgari Eloquentia ("On the Eloquence of Vernacular"), on vernacular literature, and the /Vita Nuova ("New Life"), the story of his love for Beatrice Portinari, who also served as the ultimate symbol of salvation in the Comedy. The book contains love poems in Tuscan, not a new thing; the vernacular had been used for lyric works before. But it also contains Dante's learned comments on his own prosody and these too are in the vernacular, instead of the Latin that was almost universally used.