Perhaps the most important goddess of all Egyptian mythology, Isis assumed,
during the course of Egyptian history, the attributes and functions of virtually
every other important goddess in the land. Her most important functions,
however, were those of motherhood, marital devotion, healing the sick, and the
working of magical spells and charms. She was believed to be the most powerful
magician in the universe, owing to the fact that she had learned the Secret Name
of Ra from the god himself. She was the sister and wife of Osiris, sister of
Set, and twin sister of Nephthys. She was the mother of Horus the Child
(Harpocrates), and was the protective goddess of Horus’s son Amset, protector of
the liver of the deceased.
Isis was responsible for protecting Horus from Set during his infancy; for
helping Osiris to return to life; and for assisting her husband to rule in the
land of the Dead.
Her cult seems to have originally centered, like her husband’s, at Abydos near
the Delta in the North (Lower Egypt); she was adopted into the family of Ra
early in Egyptian history by the priests of Heliopolis, but from the New Kingdom
onwards (c. 1500 BC) her worship no longer had any particular identifiable
center, and she became more or less universally worshiped, as her husband was.