Though religion was important in Aztec life, the priesthood had little secular or political influence. Most members of the priesthood were younger sons of the lords or came from lesser nobility, and they rose through the religious hierarchy by stages under the leadership of two chief priests called "Quetzalcoatl". Priests had charge of the rituals and esoteric lore associated with their temples. They were expected to live in poverty, to fast, and to draw blood from their bodies. some priests accompanied the warriors on military expeditions, others were scholars and astronomers. Diviners were a special class of priests who were not necessarily attached to temples but worked as individuals, since their ser-vices were frequently needed. They appear to have been ranked lower than the temple priests. The ruler had power over the priesthood, and could order the be-ginning of ceremonies and punish the priests. Rulers such as Motecuhzoma I and his cihuacoatl Tlacaelel modified religious cults as they saw fit. Temples and the monumental sculptures that adorned them were erected at the behest of rulers and to their specifications.