Isis is perhaps the best known and most beloved of the Ancient Egyptian Gods. She is the sister-wife of Osiris, mother of Horus, and some believe adopted as the Virgin Mary in Christian myths. 

Known as Aset, Auset or Eset in Ancient Egypt, she was the great mother Goddess and the Goddess of 10,000 names with many roles assigned to her. Her cult expanded worldwide into the British Isles and beyond. There are too many myths and legends about Isis to include them all here, but for those looking for more information about this beautiful Goddess, I'll briefly give you some of the more popular myths along with a suggested reading list and links at the end.

Ancient myths tell us that Isis was born with her twin sister Nephthys, Osiris, Set, and Horus (the elder) from the forbidden union of Nuit, the Goddess of the Sky, and Geb, the God of the Earth. Some passages in the Pyramid Texts allude to Isis having been an actual human Egyptian Queen that was deified as Gods, though the myths most commonly worshiped in Egypt say they were born as Gods. 

Both Set and Osiris fell in love with their sister, Isis, but she spurned Set in favor of Osiris becoming his wife and Queen. Set, portrayed as the evil, jealous brother in many myths (and who became the model of the Christian Devil), was constantly plotting against Osiris and was never satisfied with his marriage to Nephthys even though she was Isis' physical twin. Isis was highly honored by the Egyptians for being the noblest example of a faithful and loving wife and mother. Osiris (and later his son Horus) and Set's battles were the subject of a lot of Egyptian myths.

One of the most famous myths tells of Set triumphing over Osiris. Set was cunning and often tried to subvert his brother thru trickery and deceit (a trait that would later be transferred to the Devil). In one tale, he had the most beautiful scaraphagus (coffin) ever created presented at a dinner party with his brother. But the scaraphagus was too small for Set and he complained that no God could fit into it. Osiris disagreed and climbed in to prove his point - at which point Set slammed the lid and locked it with magic and physical chains throwing it into the river Nile. Isis immediately went in search of the coffin finding and hiding it from Set - some say it was hidden within a column which became the basis of the Djed pillar symbol for Osiris. Unfortunately, Set found the coffin again and cut Osiris up into pieces scattering him throughout Egypt. Searching far and wide, Isis recovered all pieces of her beloved husband (this period is known as Isis' Lament) except for his penis, which she fashioned from gold. Isis called about Thoth, the God of Wisdom & Magic, to help her reassemble her husband restoring him to life. Thoth taught her a spell to give her the form of a bird with her wings rushing air into Osiris' lungs bringing him back to life. In their joy of being reunited, they conceived their son Horus. Because the penis was made of gold instead of flesh, many consider this a virgin birth comparing Isis to the Virgin Mary and Horus to Jesus. The winged form of Isis became associated with funerals and protecting the body of the dead. Unfortunately Osiris was not fully alive not being able to resume his place in the mortal world and so became the God of the Underworld while his son Horus took the throne of Egypt. 

Further strengthening the connection of Isis to Mary is the story of Horus' birth. Set, enraged that Isis was pregnant by Osiris, imprisoned her in the papyrus swamps. While in prison, Thoth, who was also the God of heavenly and earthly law, gave her advice to protect both herself and her unborn child. He helped Isis escape her prison and protected her by 7 scorpion goddesses. The scorpions led Isis to a village near the swamps where a rich woman from whom she sought shelter closed the door in her face (as the Inns refused to shelter Joseph and Mary). One of the scorpion Goddesses, Tefen, was enraged and entered the womans house stinging her son to death and setting the home on fire. Isis took pity on her, restored the child to life and extinguished the fire with rain. A peasant woman, perhaps a servant of the rich woman, invited Isis to her own home.

When ready to give birth, Isis was again pursued by Set. She gave birth on a bed of papyrus plants while hiding in the swamps (similar to the manger where Jesus was born). Keeping him hidden in the swamps, she was away one day getting provisions when Set in the form of a scorpion stung Horus. Finding her son near death, she appealed to Ra, the Sun God who paused in the sky to keep Horus on the edge of death long enough for Thoth to teach Isis a spell to flush the poison from her son's body saving his life. 

Once Horus reached maturity, Horus had his own battles with Set. One battle lasted 3 days and 3 nights. Horus was on the verge of winning with Set held in chains. But Isis took pity on her brother Set and released him which enraged Horus cutting off her head. Thoth again came to her aid trasforming the decapitated head of Isis into the head of a cow reattaching it to her neck and thereby associating Isis with Hathor. 

One of the great feats of Isis is in connection with Ra, who was said to be the heavenly King of the Gods (while Osiris then Horus was the earthly King). As in many myths from around the world, it is said that to know the true name of a God is the have power over that God. Isis deceived Ra by poisoning him making him ill. She told him that in order to cure him, she had to know his true name. Finally, near death, he revealed it to her and she spoke an incantation to drain the poison from his body (perhaps the same spell Thoth had taught her to save Horus as a child). From that point, Isis was known as the Mistress of Magic. 

When Rome conquered Egypt, the Romans fell in love with many of the Egyptian myths and Isis was one of those they loved best. They spread her worship throughout the Roman Empire with a large temple in Rome itself. Often Isis was associated with other Goddesses - in Rome, she became associated with Ceres, Venus and Persephone. 

Isis is usually depicted as a beautiful woman holding a papyrus scepter in one hand and an ankh, symbol of life, in the other. Her symbol is the Tyet knot, also called the buckle of Isis, which was worn as an amulet by many in Ancient Egypt. Her crown is a pair of horns with a solar disk between them sometimes surmounted by a throne showing her as the Queen of the Gods. The horns are thought be cow horns showing her connection to Hathor or ram horns connecting her to her husband Osiris, who was represented by a Ram.  

The form of Isis with wings connects her to the protection of Osiris as he laid dead which gives her a connection to funerals and protecting the body after death. She is also sometimes depicted as a bird or Kite said which is the form she took to give Osiris life again. 

Suggested Reading and Links for More about Isis:

• Ancient Egyptian Myths and Legends - by Lewis Spence
• The Gods of the Egyptians Volume 1 and The Gods of the Egyptians Volume 2 - by E.A. Wallis Budge
• The Sacred Tradition of Ancient Egypt - by Rosemary Clark.
• Other Books about Ancient Egypt
• Isis on Wikipedia
• Goddess Isis on Encyclopedia Britannica