Mani established his religion on very broad syncretistic grounds, in the hope that it could conquer the whole oikumene, East and West, by integrating the religious traditions of all peoples—except those of the Jews. Although Manichaeism as an organized religion survived for more than a thousand years, and its geographical realm extended from North Africa to Southeast China, this ambition never came close to being realized, and the Manichaeans remained, more often than not, small and persecuted communities. Yet, in a somewhat paradoxical way, Mani did achieve his ecumenical goal. For more than half a millennium, from its birth in the third century throughout late antiquity and beyond, his religion was despised and rejected with the utmost violence by rulers and thinkers belonging to all shades of the spiritual and religious spectrum. In this sense, Manichaeism, an insane system, a “mania,” appeared as the outsider par excellence.