The goddess Isis, in Egyptian mythology, was married to her brother Osiris (just like Hera was married to her brother Zeus). Isis means “the queen”, in Egyptian. Then their enemy, the god Set, killed Osiris, and tore him apart. Set scattered Osiris’ body all over Egypt. Isis mourned for her husband/brother, and travelled all over Egypt finding the pieces of his body. Then she put the pieces back together again into Osiris, and brought him to life again. Isis and Osiris had a child, the god Horus. When Horus grew up, he fought Set with his mother’s magic spells.
This story has a lot in common with the West Asian story of Magna Mater and her husband Attis, or with the Greek story of Demeter and Persephone, or the story of Dionysos. Like them, it is a story of death and rebirth. By praying to Isis people may hope themselves to be reborn.
After the Persians conquered Egypt in 525 BC, people started to worship Isis all over the Persian Empire, as far east as Iran and what is now Pakistan. From there, the worship of Isis spread to Athens by about 350 BC. By the 200s BC more and more Greek people were worshipping Isis as a kind of mystery cult. Soon after that, people were worshipping Isis in Rome, too, and then all over the Roman Empire, from England to the Roman seaports in India. But the spread of Christianity (in the west) and Buddhism (in the east) in the 300s AD, eventually made most people forget about Isis.
Gods and Goddesses of Ancient Egypt, by Leonard Fisher (1999). For younger kids.
Isis and Osiris, by Geraldine Harris (1997). A retelling of the story for kids.
The Egypt Game (Yearling Newbery), by Zilpha Keatley Snyder (reprinted 1985). A great kids’ story about kids who pretend to be Egyptian gods and goddesses.
Religion in Ancient Egypt: Gods, Myths, and Personal Practice, by John Baines, David Silverman, and Leonard Lesko (1991). Pretty hard going, but it will tell you everything you need to know about Egyptian religion.
Isis in the Ancient World, by R.E. Witt (1997). Mostly about the spread of Isis worship to Greece and the Roman Empire.