Dante Alighieri (Italian: [ˈdante aliˈɡjɛːri]; c. May 1265 – September 14, 1321), most likely baptized Durante di Alighiero degli Alighieri and widely known and often referred to in English mononymously as Dante (English: , US: ), was an Italian poet, writer, and philosopher. His Divine Comedy, originally called Comedìa (modern Italian: Commedia) and later christened Divina by Giovanni Boccaccio, is widely considered one of the most important poems of the Middle Ages and the greatest literary work in the Italian language.

Dante is known for establishing the use of the vernacular in literature at a time when most poetry was written in Latin, which was accessible only to educated readers. His De vulgari eloquentia (On Eloquence in the Vernacular) was one of the first scholarly defenses of the vernacular. His use of the Florentine dialect for works such as The New Life (1295) and Divine Comedy helped establish the modern-day standardized Italian language. By writing his poem in the Italian vernacular rather than in Latin, Dante influenced the course of literary development, making Italian the literary language in western Europe for several centuries. His work set a precedent that important Italian writers such as Petrarch and Boccaccio would later follow.

Dante was instrumental in establishing the literature of Italy, and is considered to be among the country's national poets and the Western world's greatest literary icons. His depictions of Hell, Purgatory, and Heaven provided inspiration for the larger body of Western art and literature. He influenced English writers such as Geoffrey Chaucer, John Milton, and Alfred Tennyson, among many others.

The Divine Comedy (Italian: Divina Commedia [diˈviːna komˈmɛːdja]) is an Italian narrative poem by Dante Alighieri, begun c. 1308 and completed around 1321, shortly before the author's death. It is widely considered the pre-eminent work in Italian literature and one of the greatest works of Western literature. The poem's imaginative vision of the afterlife is representative of the medieval worldview as it existed in the Western Church by the 14th century. It helped establish the Tuscan language, in which it is written, as the standardized Italian language. It is divided into three parts: Inferno, Purgatorio, and Paradiso.

The poem discusses "the state of the soul after death and presents an image of divine justice meted out as due punishment or reward", and describes Dante's travels through Hell, Purgatory, and Heaven. Allegorically, the poem represents the soul's journey towards God, beginning with the recognition and rejection of sin (Inferno), followed by the penitent Christian life (Purgatorio), which is then followed by the soul's ascent to God (Paradiso). Dante draws on medieval Catholic theology and philosophy, especially Thomistic philosophy derived from the Summa Theologica of Thomas Aquinas.

In the poem, the pilgrim Dante is accompanied by three guides: Virgil, who represents human reason, and who guides him for all of Inferno and most of Purgatorio; Beatrice, who represents divine revelation in addition to theology, grace, and faith; and guides him from the end of Purgatorio onwards; and Saint Bernard of Clairvaux, who represents contemplative mysticism and devotion to Mary the Mother, guiding him in the final cantos of Paradiso.

The work was originally simply titled Comedìa (pronounced [komeˈdiːa], Tuscan for "Comedy") – so also in the first printed edition, published in 1472 – later adjusted to the modern Italian Commedia.