The Voyage of Saint Brendan, like its pagan predecessors, has a real and an ideal basis; and in both respects it shows an advancement over its prototypes.  It contains some very poetic touches, and is credited with being the source of some of the most effective features of Dante’s poem.  Its great popularity is shown by the fact that Caxton, the first English printer, published a translation of it in 1483; so that it was among the first books printed in English, and for that reason must have been one of the best-known works of the time.  Dante undoubtedly knew it, for he was a great scholar in the learning of his day, and especially in ecclesiastical history and the biography of saints.

Another vision of Irish origin that Dante and other writers have borrowed from is that of an Irish soldier named Tundale.  He is said to have been a very wicked and proud man, who refused to a friend who owed him for three horses an extension of time in which to pay for them.  For this he was struck down by an invisible hand so that he remained apparently dead from Wednesday till Saturday, when he revived and told a story of a visit to the world of the dead that has many features later embodied in the Divine Comedy.  Tundale’s vision is said to have taken place in 1149; Dante probably wrote his poem between 1314 and 1321.

The Irish also produced another legend of this sort that was enormously and universally popular, and became the chief authority on the nature of heaven and hell, in the story of Saint Patrick’s Purgatory.  Saint Patrick was said to have been granted a view of heaven and hell, and a certain island in Lough Derg in Donegal was reputed to be the spot in which he had begun his journey; and there, it was said, those who desired to purge themselves of their sins could enter as he had entered and come back to the world again, provided their faith was strong enough.

This legend was probably known in Ireland from a very early time, but it had spread over all western Europe by the twelfth century.  Henry of Saltrey, a Benedictine monk of the Abbey of that name in England, wrote an account in Latin of the descent of an Irish soldier named Owen into Saint Patrick’s Purgatory in 1153; and this story soon became the subject of poetic treatment all over Europe.  We have several French versions, one by the celebrated French poetess Marie de France, who lived about 1200; and there are others in all the languages of Europe, besides evidence of its wide circulation in the original Latin.  Its importance is shown by the fact that it is mentioned by Matthew Paris, the chief English historian of the thirteenth century, and also by Froissart, the well-known French annalist of the fourteenth while Calderon, the great Spanish dramatist, has written a play based on the legend.  Dante undoubtedly knew of Marie de France’s version as well as the original of Henry of Saltrey and probably others besides.