 During the reign of Shapur, Manichaeism, a new religion founded by the Iranian prophet Mani, flourished.Mani was treated well by Shapur, and in 242, the prophet joined the Sasanian court, where he tried to convert Shapur by dedicating his only work written in Middle Persian, known as the "Shabuhragan".Shapur, however, did not convert to Manichaeanism and remained a Zoroastrian.