The story of Barlaam and Josaphat or Joasaph is a Christianized and later version of the story of Siddhartha 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. In the Slavic tradition of the Eastern Orthodox Church, these two are commemorated on 19 November (corresponding to 2 December on the Gregorian calendar).