Roman religion involved sacrificing animals to the gods. The animals were killed in a ritual manner; they would be led to the altar, hit from behind with a blow from a hammer, and their throat then slit. The portion of meat and fat to be offered would then be burned so that the smoke could rise to the gods. The offering might also include incense and libations of wine or other liquids. White animals, such as the white bulls described here, were popular choices for sacrifice because of their symbolic purity.