So at the terrible glance from the Eye of Re his daughter Sekhmet came into being, the fiercest of all goddesses. Like a lion she rushed upon her prey, and her chief delight was in slaughter, and her pleasure was in blood. At the bidding of Re she came into Upper and Lower Egypt to slay those who had scorned and isobeyed him: she killed them among the mountains which lie on either side of the Nile, and down beside the river, and in the burning deserts. All whom she saw she slew, rejoicing in slaughter and the taste of blood.1
Her name is derived from sekhem, which translates to 'power,' or 'might.'2 She is also called Lady of the West3, Eye of Ra2, Nesert ('the flame')2, Lady of Terror2, Lady of Life2, One Who Loves Ma'at and Who Detests Evil2, Destroyer2, Lady of Pestilence2, Red Lady2, Mistress Lady of the Tomb2, Gracious One2, and Mighty One of Enchantments2, among others.
Sekhmet is said to have come into being when Re saw that humans were disobeying the laws he had laid out for them. Re called together the gods Shu, Tefnut, Geb, and Nut, and also Nun. The gods held a council to see what could be done.
Re spoke to Nun before the assembled gods: "Eldest of the gods, you who made me; and you gods whom I have made: look upon mankind who came into being at a glance of my Eye. See how men plot against me; hear what they say of me; tell me what I should do to them. For I will not destroy mankind until I have heard what you advise."
Then Nun said: "My son Re, the god greater than he who made him and mightier than those whom he has created, turn your mighty Eye upon them and send destruction upon them in the form of your daughter, the goddess Sekhmet."1.
At which point Sekhmet was sent off to avenge until there was no tomorrow -- which very nearly happened. But Re took pity upon mankind, and decided to stop Sekhmet's slaughter. He got all the women of Heliopolis ("the city of Re where stand the stone obelisks with points of gold that are like fingers pointing to the sun"1) to brew beer all day. Then he had them mix the beer with red ochre, to make it look like blood, and the women did as Re commanded. During the night they took the red beer and brought it to Sekhmet. She, thinking it was the blood of those she had slain, drank all seven thousand jars of it1, and was drunk in no time. She was so drunk that she could not slay anymore.
Then Re said: "You come in peace, sweet one." And her name was changed to Hathor, and her nature was changed also to the sweetness of love and the strength of desire. And henceforth Hathor laid low men and women only with the great power of love. But for ever after her priestesses drank in her honour of the beer of Heliopolis coloured with the red ochre of Elephantine when they celebrated her festival each New Year.1
But the Egyptian people feared that Sekhmet might return in all her fury, and so they came up with a way to appease her. It involved more than 700 statues of the goddess before which her priests had to perform a ritual. The catch, though, was that the priests had to do this before a different statue, morning and afternoon, every single day of the year.3 During the New Kingdom, thousands of statues of Sekhmet, carved from Aswan red granite, were erected to line processional ways as a way of encouraging her to rid the people of plagues that had come into the country.5
Sekhmet is usually depicted as a woman with the head of a lioness, sometimes crowned with the sun disc Sitting, she holds an ankh; striding or standing, a sceptre made from papyrus, the symbol of Lower Egypt. She is sometimes associated with Bast, the general idea being that they are the goddesses of Lower and Upper Egypt, respectively. Nevertheless, despite the similarities between the two, they should be considered separate, individual deities. Besides, Bast was said to wear green, while Sekhmet wore red.3
While this difference may seem slight, colour was often very important in ancient Egypt -- the colour was a clue to the heart of the matter. When they said that you could never know the colour of the gods, they meant that the gods' nature could never be completely understood. This is why the colour difference between what Bast wears and what Sekhmet wears is important in distinguishing the one from the other. In art, especially, we are given clues as to the nature of beings by what colours they are portrayed in. For example, when Osiris is depicted with green skin, it is a reference to his power over vegetation as well as his resurrection. Green, you see, is the colour of joy and new life, and is also associated with the "land of the blessed dead." To do "green things" meant that you were doing things that were beneficial and health-bringing.4
Sekhmet, however, was not green. Red, for the Scarlet Lady, is the colour of life in a rather different way. This is victory, the colour of the ochre with which the Egyptians adorned themselves at celebrations. This is strength, the colour of Seth's hair and eyes, the colour of the blood in our veins -- the blood that Sekhmet drinks. This is rage and anger and fire, and "to redden" meant "to die." This is the sun, which warms, but also burns.4
Sekhmet herself is very much like the colour she wears. As the Lady of Pestilence, she can bring disease, but also keep it away. Her power could be invoked for healing -- her ability to destroy things utterly and completely could be used to destroy illness. In fact, many of Sekhmet's priests were very well-trained surgeons. Sekhmet's consort is Ptah, the creator, and her son is Nefertum, the healer.5 So she is not so much the random slaughterer, but rather the bringer of necessary destruction and a sort of purification through destruction. That said, it must be remembered that the Red Lady is a lioness, and not something that can be tamed.
"Oh! Sekhmet, Eye of Re, Great of Flame, Lady of Terror, who surrounds her creator." -Temple of Edfu6