Hu is mentioned already in the Old KingdomPyramid Texts (PT 251, PT 697) as companion of the deceased pharaoh. Together with Sia, he was depicted in the retinue of Thoth, with whom he was also occasionally identified.
In the Middle Kingdom, all gods participated in Hu and Sia, and were associated with Ptah who created the universe by uttering the word of creation. Hu was depicted in human shape, as a falcon, or as a man with a ram's head.
In the New Kingdom, both Hu and Sia together with Heka, Irer and Sedjem were members of the fourteen creative powers of Amun-Ra. By the time of Ptolemaic Egypt, Hu had merged with Shu (air).
Wilkinson, R. H., Die Welt der Götter im Alten Ägypten. Glaube - Macht - Mythologie, Stuttgart 2003