Hmmm.... that's a good question!
I think Jadis was more advanced and more interested in dark magic than her sister. After all, she had discovered the deplorable word, and I don't believe her sister knew it. That spell would be one that would really have to be sought after, not just one you could find in a magic book. I don't think her sister was in the right either, (in fact, I do not doubt that she used magic) but I don't think she cared as much about the magic as Jadis did. I have the impression that Jadis was the younger sibling (does the book say this or was it just an impression of mine?), and therefore the right to the throne would not be hers.

Snippets of Jadis' account:
It was my sister's fault. She drove me to it. At any moment, I was ready to make peace - yes and to spare her life too, if only she would yield me the throne.... Her pride has destroyed the whole world.... a solemn promise that neither side would use Magic. But when she broke her promise, what could I do?... She even knew that I had the secret of the Deplorable Word.... she was always a weakling.... I learned it in a secret place and paid a terrible price to learn it. I did not use it until she forced me to it.... I did not use my power till the last of my soldiers had fallen....I waited till we ...could see one another's faces. "Victory." "Yes," said I, "Victory, but not yours." Then I spoke the Deplorable Word....

Nothing on which was older. Jadis was decidedly the greater student of Magic. And the sister was, according to the account, probably just as power-hungry as Jadis.

I think I just assumed that the throne was rightfully the sister's (since I don't trust Jadis' account), meaning that the sister would be older most likely (at least, in my mind)....

The fact that Jadis mentioned temples makes me curious about what sort of religion(s) they had in Charn. Ideas, anyone?

Well... I think polytheistic is a given. Maybe also some theocratic overlap with minor magic-blooded royalty being used as priesthood (thus able to manufacture miracles to bolster the faith and fear of the commoners), and possibly ancestor-worship of the jinn who helped birth the royal line? I wouldn't be too surprised with the magic-blood royalty thing and the large standing armies available when Jadis and her sister went up against eachother if gods related to magic and to war were highly revered...

Ariel? What do you think?

Haha, um... I've never really thought about it before. I really liked what you said about the "magic-blood royalty thing".Because I've always (to an extent) likened Jadis to Satan (as that's the role she plays in LWW), I never really wondered about the whole religion-in-Charn thing (until I posted the question, obviously). I mean, I know that she's not an exact parallel in many ways; it just never crossed my mind.I imagine that magic itself may have been worshipped, especially as the uses thereof grew darker and darker. Magic seems almost like an entity rather than just a tool or a natural law (maybe it's so to Aslan too, I don't know; I kind of think that Jadis seemed maybe more inclined to the entity idea somehow; maybe I'm wrong and am just rambling haha).I'm also wondering if maybe they didn't have... physical gods (like Tash). Maybe they did, but for some reason, I'm not fully envisioning Jadis making sacrifices to an idol so much as to an idea. War itself, Love itself, Wind itself, etc. May be a little hard to do without an entity to attach it to though, I don't know. Maybe I'm just over-thinking. ;-D

On the Jadis/sister conflict... I don't think the sister was a saint, but I'm not sure how dark she was, either... it might have been black and black morality, or black and gray-ish morality, so to speak. Like, the sister could have been sick and tired of watching her men get slaughtered, and convinced herself that a little magic-working--maybe something she thought her sister wouldn't notice--was the only way to break the stalemate. It seems like if she knew Jadis has The Deplorable Word, and still used magic, she must have either believed that it was something Jadis wouldn't see, or misjudged her sister's resolve... believed that not even Jadis would really genocide the entire planet she meant to rule. Or possibly both, betting that IF Jadis saw, she wouldn't play the trump card.

I know that's a bit on thin ice. Weighing one level of wrong against the wrongness of another.

No kidding. (Explain to me why I'm crazy enough to write a fic about this?!)
The more I think about it, the less "good-guy" the sister becomes. She's definitely part of the increasingly dark trend found in the later royals of Charn. I don't think she had any more regard for life than Jadis did; in fact, I think if she knew the Deplorable Word, she might have resorted to it if pushed far enough.
Anyone else think it's odd that Jadis upheld the promise until the very end?

Is it?
Perhaps even "evil" characters have a code of honor.
Jadis approved her ancestor's murder of his nobles apparently on the basis that he believed they were plotting treason. She thought there was a proper order to things--magicians with the proper look and blood were to be respected, and to some extent, honored (she was not looking to make a hostile takeover from Digory's magician uncle, although she thought she still had all of her powers, when she believed he was a 'real' magician), and book-learned magicians were worth dirt and ought to be exterminated or enslaved. She liked to look like she was obeying the rules: she claimed Adam's blood when she enthroned herself in Narnia, and appealed to the Deep Magic for her right to execute Edmund. For such a person, it might make sense to honor a pact made with her royal magician opponent sister--especially when she knew that she had all the cards in her hand, and could afford to bide her time until said "weak" sister gave out.

Of course, I could just be overanalysing things, but I find overanalysis fun. ^_^

Good points, Lily. And after all, doesn't the Devil make himself seem totally right and twist it all to his purpose?
Hey, what else is this thread for but to analyze and overanalyze? 😀

^_^

You say you're writing a fic about this... I'm a bit curious who is the main character. Are you mostly focusing on Jadis, or her sister, or a bystander in one of their armies?

I've had a Charn-fic percolating in my head, also--but not focused on the Last War. And I'm not sure how soon it would be a good idea for me to be acting on it.

Well, not writing, per se, but it's on my list of well-over-100 fic ideas. I've not decided which pov to go with (either the sister's or alternating between them). It would require a load of thought and frequenting this thread. 😉 Also, I've got some in-progress fics that should probably be taken care of before I start another.

Ah, alrighty. 🙂
I'm not sure if my fic ideas are up to 100--I shall need to count sometime--but I do think I know the feeling.
I am glad that the thread can be of some use in your brainstorming.

Fascinating discussion 🙂
The main reason I would imagine the sister to be in the right (or more in the right) is that Jadis is going to such lengths to try to justify her actions. Saying that the sister would not yield the throne does not sound as if it was Jadis's by right. Jadis would have said clearly that the throne was hers by law if it had been. The sister may have broken the magic truce, but there is also a decent possibility that she cared some for the people.

I don't like either one of them. 🙂