In the early fourteenth century, written Italian began to take form through the works of Dante Alighieri (1265-1321). A towering figure of world literature, Dante is best known for his allegorical work La divina commedia (The Divine Comedy), which he began circa 1307 and worked on until his death. La commedia traces Dante's imaginary journey through Hell, Purgatory, and Heaven, during which he encounters historical and mythological creatures, each symbolic of a particular fault or virtue.

Dante's Latin treatise De vulgari eloquentia (c. 1303) promoted vernacular Italian as a literary language fit to replace Latin. La divina commedia, written in Italian verse, proved Dante's argument.

Dante's native Tuscan dialect was strongly influenced by the dialects of the court poets of the Sicilian School, whom Dante greatly admired. Given the dominant economic role of the Tuscan city-states in the fourteenth century, the influence of the Tuscan dialect spread. Italian, previously treated as a spoken dialect, was recognized as a language to rival Latin, and The Divine Comedy has remained one of the world's greatest works of literature.