Horus — Egyptian Hor, meaning "the distant one" or "the one on high" — is one of the earliest attested deities in Egyptian religion, appearing in royal names and inscriptions from the very beginning of the dynastic period. His primary symbol is the falcon — the bird that soars highest in the Egyptian sky, whose eyes appear to contain the sun and moon. When a falcon was spotted circling high above, the Egyptians understood they were seeing Horus himself.
In the great mythological narrative that organises Egyptian theology — the Osiris cycle — Horus is the son of Osiris (the murdered divine king) and Isis (the supreme magician). After Osiris is killed and dismembered by his brother Set, Isis gathers the pieces, temporarily resurrects him, and conceives Horus. She hides the infant Horus in the papyrus marshes of the Nile Delta, protecting him from Set, and raises him in secret. When Horus comes of age, he challenges Set for the throne of Egypt — a contest that occupies the gods' tribunal for eighty years before Horus is declared the rightful king.
The identification of the living pharaoh with Horus is one of the oldest and most enduring theological ideas in Egyptian civilisation. From the very earliest dynasties, the pharaoh bore a "Horus name" as his first royal name — identifying him as the earthly manifestation of the falcon god. When the pharaoh died, he became Osiris (passing the Horus identity to his successor). This theological structure — the living king as Horus, the dead king as Osiris — provided the framework for understanding Egyptian kingship, death and succession for over three millennia.
Horus has two eyes of cosmic significance: his right eye is the sun (identified with Ra), and his left eye is the moon. The moon's phases are explained mythologically as the result of Set's damage to Horus's left eye during their battle — Thoth restores it each month as the moon waxes. The Wadjet — the Eye of Horus — became one of the most powerful protective symbols in all of Egyptian religion and remains one of the most recognised symbols in the world today.