Likely begun immediately after the completion of the Inferno, Dante Alighieri's epic poem the Purgatorio is the second of the three canticles (sets of cantos) which make up the Divine Comedy or the Commedia. It follows Dante and Virgil as they exit Hell and make their way up the mountain of Purgatory, on which saved souls repent before entering Heaven. As with the Inferno, the poem allegorizes Dante's own spiritual journey; his ascent up the mountain of Purgatory is also a movement towards his own repentance, which is dramatized in the canticle's climactic interactions with Beatrice, his beloved and the woman who will come to guide him through Heaven in the final book of the Commedia, the Paradiso.
According to Marco Santagata, it appears the Purgatorio was written sometime in either 1308 or 1309, when Dante was in exile in Lucca, Italy. Though little is known of the specifics of its composition, it seems likely that at the time of writing, Dante had given up hope of being able to return to Florence. It appears that without the need to impress the powerful Guelfs, Dante used the Purgatorio to explicate his own complex politics more explicitly, which were in support of the Holy Roman Empire and critical of both the Church and the burgeoning market-based economy. While we know few specifics of Dante's life at the time, we do know he was actively and critically integrating the events of his day into the Purgatorio, which features a number of figures who had died only recently.
Less commonly read than the Inferno, it remains a classic work of Italian literature, one of the most widely read medieval works, and an important part of the Commedia as a whole. Just as in the Inferno, the Purgatorio reveals Dante's power both as a poet and a philosopher; the poem weaves visceral description into theological explorations with ease. Indeed, the Purgatorio has been so influential that typical understandings of Purgatory seem to have been concretized largely by Dante's work, which developed the spiritual plane further than many had prior to his writing the poem. Yet its influence and popularity stretch even further: Samuel Beckett famously integrated Belacqua, a figure from the Purgatorio, into many of his works, and more recently, the poet W. S. Merwin translated the Purgatorio into English.