Medievalist Jacques Le Goffdefines the “birth of purgatory”, i.e. the conception of purgatory as a physical place, rather than merely as a state, as occurring between 1170 and 1200. Le Goff acknowledged that the notion of purification after death, without the medieval notion of a physical place, existed in antiquity, arguing specifically that Clement of Alexandria, and his pupil Origen of Alexandria, derived their view from a combination of biblical teachings, though he considered vague concepts of purifying and punishing fire to predate Christianity.
While the idea of purgatory as a process of cleansing thus dated back to early Christianity, the 12th century was the heyday of medieval otherworld-journey narratives such as the Irish Visio Tnugdali, and of pilgrims’ tales about St. Patrick’s Purgatory, a cavelike entrance to purgatory on a remote island in Ireland. The legend of St Patrick’s Purgatory written in that century by Hugh of Saltry, also known as Henry of Sawtry, was “part of a huge, repetitive contemporary genre of literature of which the most familiar today is Dante’s”; another is the Visio Tnugdali.
Other legends localized the entrance to Purgatory in places such as a cave on the volcanic Mount Etna in Sicily. Thus the idea of purgatory as a physical place became widespread on a popular level, and was defended also by some theologians.
image: Image of a fiery purgatory in the Très Riches Heures du Duc de Berry