Born of the controversy over the Incarnation, christologically unorthodox but fervent in mission and evangel, the Assyrian (Syriac-speaking, Nestorian) Church carried its particular version of the Gospel from its first center in Mesopotamian Edessa Callirrhoe, and its second in Nisibis, to earth's remotest known ends. Repudiated and anathematized for Nestorianism* by Western Christendom (, 431), and harried out of the , these sectarians advanced ultimately to China and India, making tremendous impact. They suffered innumerable persecutions, culminating in the Kurdistan mountains in World War I. Settled in Edessa long before 431, they expanded to Nisibis in 435, but lost the Edessa foothold in 489-which merely sparked astounding missionary expansion. Celibacy was originally essential, even for laymen seeking baptism. By a decree in 499, clergy, including bishops, received sanction to marry, and some did this, much to the scandal of the Roman Church. The mendicant praying monks (Euchites) were probably lazy rather than immoral, as enemies unkindly insinuated. Lofty in ideals, they have similarities with later Quietists and perfectionists.