A triad is an association of three kindred or correlated deities. In ancient Egypt, cycles of this type usually arose out of the association with the chief local god of other deities; in some instances the members were deemed to stand in the relationship of father, mother and child. Such were the Theban triad of Amen, Nut and Khons; the Memphite of Ptah, Sekhet and Nefertum; and the Osiris-Isis-Horus triad, which, n the Alexandrian form, comprised Serapis, Isis and Harpocrates.
In Babylonia, triads were derived from early conceptions of a cosmic trinity, such as Anu, Enlil and Ea representing sky, earth and water: and shin, Shamash and Ishtar, representing sun, moon and star. Early Aryan thought moved in the same direction in the Vedic triad of Agni, Indra and Surya, representing fire, wind and sun. out of this emerged the Brahman Trimurti, or three aspects, portrayed as a three-headed image in a famous sculpture at Elephanta, and comprising Brahma, the creator, Vishnu the preserver, and Siva the destroyer.
Buddhism adopted the principle in the Triratna, or three jewels, which were at first the Sangha or monastic order, portrayed as a man holding a lotus, the Buddha, and the Dharma, or sacred law.
The Triad Society of China, denoting the union of heaven, earth and man arose in the 18th century and became a powerful anti-dynastic movement. Research Triad