WARNING: This article contains spoilers through Season Three's "The Devil You Know." Proceed with caution!
A lesser-known figure in Egyptian myth, Sokar's purpose in "Stargate SG-1" is a very prototypical one. That is, he is the generic mold that his later successors would use in creating their own image. While we learn of his Egyptian origins in "Serpent's Song," later episodes ("Jolinar's Memories" and "The Devil You Know") only reaffirm the fact that he is a Goa'uld taking on the title of Lord of Death (in many cultures) - and that he is the Devil.
In true mythology, Sokar was the guardian of the necropolis near the city of Memphis and he was depicted as a hawk-headed mummy. More specifically, he was a local deity, serving that city at an earlier time even before it was built. Thus, he was one of the original gods to be associated with the realm of the dead and the underworld.
In a physical context, he was primarily associated with the darkness and decay of the tomb itself.1 That is, he was a personification of nothing changing and nothing moving (i.e. inertia and inaction). Appropriately enough, in that context, he was feared. However, as a guardian, he was also respected and worshipped.
As a funerary god, his worship probably even predated that of Osiris because the two served a similar purpose. In a later period (the Middle Kingdom in Ancient Egypt), the worship of these two deities was linked and it was believed that Sokar was the mysterious form of Osiris.2 Quite possibly, Osiris needed a new name to identify him when he became the new Lord of the Underworld. Thus, the name of Sokar was used by Osiris to become much feared.3
Theoretically, this included not only fellow gods but also his worshippers because there were even spells to ward off an angry Osiris from the tombs.4
In a later period, when Ptah (a creation deity) became the principle god worshipped in Memphis, he was sometimes amalgamated with Sokar to form a new god -- Ptah-Seker. To note, Seker was the spelling used by the Egyptians to identify this dark god. The compounding of names was interesting because there also was another form, Ptah-Seker-Osiris. Depicted in art, he appeared as a dwarfish figure with a beetle on his head.
These other forms mostly affirmed the similarities these three gods had. The commonly represented the life-death cycle of the crops. That is, at their simplest level of definition, they were agricultural gods.5
When placing these facts to Stargate's interpretation of the deity, the information Daniel Jackson states is very muddled. "[Sokar] was the most feared deity in ancient Egypt, the original god of death."6 While true in a general sense, the title was held by another god, Anubis, guardian of the dead and bringer of souls to the afterlife.7
But when Daniel continues, "According to the Book of the Dead, there was a time when he ruled all of Earth," the rest does not make sense unless Sokar is revealed to be another form of Osiris. In the myth, before his murder, he did come to rule most of the Two-Lands (i.e. Osiris wanted to bring civilization to all of Earth).
However, with this fact unacknowledged in the television series, Sokar is more generalized. Even if Osiris is acknowledged, there would be a continuity problem because of the recent episode "The Curse." He is introduced into the Stargate mythos as his own unique personality and that he ruled his own world without any assistance from other Goa'ulds, save for his queen.
The explanation of Sokar's lands is confusing because it is more of an accurate description of Tuat (the Egyptian netherworld) than of Hell on Earth. Daniel states, "His lands on Memphis were covered by darkness and inhabited by serpents," and later mentions, "his portion of Tuat was filled with lakes of fire where the wicked were thrown in as punishment after torture and mutilation." While this latter line is an apt description of the world of Netu, in all its atypical glory, it is a fictionalized world with all its Egyptian influence gone.8 For Jack O'Neill, he neatly generalizes and summarizes this world in one word: Hell.
An important note to make is that the Ancient Egyptians believed that there were many hells.9 Each region was unique such that they had their own unique topography, allowing for lakes of fire and steaming pits. In these other Hells, darkness was absolute and within it existed nightmarish beings, serpents and Apophis. In that regard, it is no surprise to find Apophis in the later episodes, "Jolinar's Memories" and "The Devil You Know," when the SG-1 team ventures into the underground world of Netu.
Jackson concludes, "Basically he was the original Satan." But the similarities between the Devil and Sokar are very far-fetched and probably based on the phrase "the rebel who did evil is driven off" in the Book of the Dead.10
Although Satan has often been regarded as a rebel of Heaven, none of them are appropriate to his overall role in literature.
As an archetype, Satan is a Trickster figure, a deceiver.11 In the New Testament, he was better known as the Adversary. Historically, early Christians -- the Hebrews specifically -- tagged another Egyptian deity, Seth, as Satan (rather than Sokar).12 None of these describes the role that the Stargate series placed him in.
As a prototypical lord of the underworld, Sokar was more menacing in reference than in person. Perhaps the most memorable moment was when the holographic image of his demonicface manifested through the iris.13 When we finally meet him, he is a bald headed Goa'uld with veins showing on his face and there are no statues depicting him according to Egyptian legend. The later episodes pretty much decide to forget his Egyptian heritage, favoring traditional cinematic motifs to depict Hell.
With most of his background and portrayal generalized, Sokar is left as a prototype so that there would be successors like Osiris and Apophis to fill in the gaps. Appropriately enough, Apophis does succeed at the end of the episode "The Devil You Know." He now rules the darkness that encompasses and the forces of Hell.
Hopefully Osiris will one day reappear and attempt to lay claim to Apophis' forces because he believes he should rule the underworld again, before taking vengeance upon all of Earth. To stay mildly faithful to the original death god's origins, it would be interesting to have Osiris pose as Sokar and be more of a sinister background presence, bringing confusion to the SG-1 team and the serpent god until the secret is revealed.
1. Watterson, Barbera, Gods of Ancient Egypt, 170
2. Clark, R.T. Bundle, Myth and Symbol of Ancient Egypt, 109
3. Faulkner, Raymond., Egyptian Book of the Dead., Plate 2 "Hymn to Osiris"
4. Sum, Ed., Osiris : Part One
5. Ibid., 97 See also, Shorter, Alan., The Egyptian Gods, 37
6. Stargate SG-1 : "Serpent's Song"
7. Armour, Robert., Gods and Myths of Ancient Egypt, 168. Also, Anubis' role was downgraded in the Stargate movie; he was simply a soldier of Ra.
9. One such place was Neter-khertet (meaning: divine subterranean place.) which the planet of Netu probably draws its name from.
9. Clark, R.T., Myth and Symbol in Ancient Egypt., 32
10. Faulkner, Raymond., Egyptian Book of the Dead., Plate 19
11. Rev. 12:9
13. Stargate SG-1 : "Serpent's Song"