thumb|A 14th-century illustration of the execution of Mani While Manichaeism was spreading, existing religions such as Zoroastrianism were still prevalent, and Christianity was gaining social and political influence. Although having fewer adherents, Manichaeism won the support of many high-ranking political figures. With the assistance of the Sasanian Empire, Mani began missionary expeditions. After failing to win the favour of the next generation of Persian royalty and incurring the disapproval of the Zoroastrian clergy, Mani is reported to have died in prison awaiting execution by the Persian emperor Bahram I. The date of his death is estimated at 276–277 CE.
thumb|A 14th-century illustration of the execution of Mani While Manichaeism was spreading, existing religions such as Zoroastrianism were still prevalent, and Christianity was gaining social and political ,influence. Although having fewer adherents, Manichaeism won the support of many high-ranking political figures. With the assistance of the Sasanian Empire Mani began missionary expeditions. After failing to win the favour of the next generation of Persian royalty and incurring the disapproval of the Zoroastrian clergy, Mani is reported to have died in prison awaiting execution by the Persian emperor Bahram I. The date of his death is estimated at 276–277 CE