Child deities constitute a unique class of divinities in Egyptian religion. A child deity is the child member (usually male) in a divine triad, constituting a family of father, mother, and child. The theology of child deities centered on fertility, abundance, and the legitimation of royal and hereditary succession. Child deities grew in importance in temple cult and popular worship in the first millennium BCE and became particularly prominent in the Ptolemaic and Roman Periods.