Barlaam and Josaphat is a Christianized version of the story of Siddharta Gautama, who became the Buddha. In the Middle Ages the two were treated as Christian saints, being entered in the Greek Orthodox calendar on 26 August, and in the Roman Martyrology in the Western Church as "Barlaam and Josaphat" on the date of 27 November.

According to the legend, King Abenner or Avenier in India persecuted the Christian Church in his realm, founded by the Apostle Thomas. When astrologers predicted that his own son would some day become a Christian, Abenner had the young prince Josaphat isolated from external contact. Despite the imprisonment, Josaphat met the hermit Saint Barlaam and converted to Christianity. Josaphat kept his faith even in the face of his father's anger and persuasion. Eventually Abenner converted, turned over his throne to Josaphat, and retired to the desert to become a hermit. Josaphat himself later abdicated and went into seclusion with his old teacher Barlaam.

Cf. http://en.wikipedia.org/wiki/Barlaam_and_Ioasaph