In Egyptian mythology, Shu (meaning emptiness and he who rises up) is one of the primordial gods, a personification of air, one of the Ennead of Heliopolis. He was created by Atum, his father and Iusaaset, his mother in the city of Heliopolis. With his sister, Tefnut (moisture), he was the father of Nut and Geb. His daughter, Nut, was the sky goddess whom he held over the Earth (Geb), separating the two.
As the air, Shu was considered to be cooling, and thus calming, influence, and pacifier. Due to the association with air, calm, and thus Ma'at (truth, justice and order), Shu was portrayed in art as wearing an ostrich feather. Shu was seen with 1-4 feathers.
In a much later myth, representing the terrible weather disaster at the end of the Old Kingdom, it was said that Tefnut and Shu once argued, and Tefnut (moisture) left Egypt for Nubia (which was always more temperate). It was said that Shu quickly decided that he missed her, but she changed into a cat that destroyed any man or god that approached. Thoth, disguised, eventually succeeded in convincing her to return. He carries an Ankh, the symbol of life.