"Who was prior warden" has been a popular discussion. I've seen some fan-theories, but none have fully convinced me. LaFortier is a popular one, and I've thought it one of the better ones: LaFortier being murdered not just to frame Luccio but (in the bigger picture) to remove the Warden, so someone else (e.g. Cowl) could move in and become Warden.
See below for the
Bold Italic Underlined bit (
B+
I+
U added by me for emphasis) in that final paragraph...
Priscellie:
In terms of how long someone is a warden, I'm sure it varies from case to case but how long does wardenship typically last?
Jim:
It depends on how quickly it gets you killed.
Priscellie:
Is that the only way out?
Jim:
I'd say it's not the only way out. You can definitely walk away from it or be dragged away from it or driven away from it. And then if somebody else comes along and challenges Demonreach then it's their island if your influence isn't there anymore. By the time Harry got there nobody had been there in a good long while because among the people who are in the know on the council it would be suicide to go try and do that. If one of the senior council guys got it all the other senior council guys would be like "yep he's the bad guy he's definitely corrupt and serving evil". And then Dresden walked into it and it was just such a stupid move they all kind of looked at him and went "I think he was he was being dumb? Do you think he was being dumb? Yeah it looks dumb. It looks like he was just being stupid, oh my god, we do need the firepower", you know, like that. The poor council, they find themselves so strapped for resources in so many ways that they keep having to tolerate Harry Dresden.
So: nobody was Warden for "a good long while" before Harry.
Kemmler had been Warden up until 1961; then there were two others; then the gap (until Harry).
I think we can presume those two are known figures, named characters, in the Dresdenverse. Possibly even significant ones (unlike the minor figure of LaFortier, whose only named/onscreen role is as "Mr. Body"). PROBABLY significant ones, since IIRC Jim has dodged this question more than once.
Was Margaret LeFay once a Warden of the island? Maybe she lost it during some deep-Nevernever time-dilation, someone moved in & sniped it?
Maybe Ebenezer sniped it, to "save" her from the darkness there? Then just... walked away, as Jim says can be done?
What about Justin? Dark power looks right up his alley...
Can a nonwizard become Warden?
Maybe a Whampire, or a Faerie?
Because if we rule out the Senior Council (which WoJ says would push the other SC's to DefCon5) there aren't a lot of named wizards that could manage the deed... Fewer still whom Jim would be so squirrely about not naming...