So, for the time being, I pretty much dominate the #alternate jewish history tag. By which I mean, all posts under this tag are ones I either wrote or reblogged. This is, of course, meaningless. Even so, I intend to take care of this little corner of my supposed kingdom, though invaders are fully invited. Please, it would be my pleasure if you add to this tag.
Either way, this tag currently has three AUs. As the purported owner of this tag, I intend to list them - while tagging the original creator when necessary.
The first AU is going to be the one I conceived of, naturally, since there can be no ownership disputations of it: the Jewsade.
The Jewsade is an AU based on the historical divergence of His Dark Materials. However, it's an AU worth exploring for its own merit IMO. Its divergence point is around the 1520s, with the Jewish false Messiah David Reubeni and Shəlomoh Molcho. In our world those two ended up eventually killed by the Spanish Inquisition; in the world of the Jewsade, they succeeded in getting the artillery David was trying to obtain and used it to conquer Eretz Yisra'el from the Ottomans. What happened with it later? Currently it's a riddle I can't answer, possibilities range from a disaster by the hands of the Ottoman Empire or Portugal to the continued existence of a Jewish kingdom in the Middle East, barely holding its own against both Christians and Muslims who want to take the Holy Land to themselves. Exploration of it is still at work, and I'm considering presenting it in random documents of various sorts from the period. It doesn't currently have a clear masterpost, I might work on that in the future.
The second AU I've put under this tag belongs to @aviad1b. This is the Hasmonean independence AU. It's not too well-built as of yet (and might also be related to the next AU, we'll see), but the basics are: the Hasmoneans don't give up their independence to the Romans and remain a kingdom for longer. This is a bit of a hard feat, because the Hasmoneans were sort of allies to the Romans even prior to that and the civil war is what caused them to turn to a passing Roman general to solve the dispute. After you avoid that... well, the Hasmonean dynasty still needs to keep its independence between the ever-greedy Rome and the rising Perthian empire, which is not going to be easy by any means. Even if they manage surviving one civil war... well, there will be others. However, it might be interesting to picture them somehow still prevailing, despite all the odds.
The third and more recent addition comes from @magnetothemagnificent's idea of a world where the 2nd Temple was never destroyed, the 2nd Temple Still Standing AU as I chose to call it, if you have different suggestions I'm open to hear them. A lot of the discussion on it includes the note of how much we don't know what the world will look like. Christianity might not exist, or be way smaller. The Jewish Diaspora would be way smaller adn would be mostly merchants. New technologies would be applied to old traditions and sometimes adjusted to them - the beacons to indicate the start of the month will stay, but their role would be fulfilled more with modern communication technology; flights to Eretz Yisra'el will commonly have space for cattle for the Korbanot; Cohanim would dominate the field of dermatology in order to be experts on Tzara`at, some working in construction (and some with textiles?) for the other types of it as well; religious institutions will be vastly different, with structures from 2 milennia ago surviving to the Modern Day in some form; Levyim maybe being dominant in fields of music and poetry; maybe melodies used for written texts in the place of punctuation; no written Mishnah or Talmud, things are mostly kept oral; and a lot more stuff.
There's the question, with that latter AU, of how that might happen. No rebellion against the Romans might be a possibility, though a bit hard to pull up. The Hasmonean Dynasty retaining independence can help, hence the reference I've made earlier. The Great Rebellion could also (maybe) fail before it escalated to the level of besiegeing Jerusalem. I really don't know. And unless you go by the "History is a rubber band" theory of time travel, there really isn't any way to know. So I suppose we should all just think about it a little more, and making stuff up can work, as long as you keep an eye on historical events.
Edit: a bit late, but we're adding Atlantean Jews! I said I would a while ago, but didn't get to it. However, here I am now. The basic concept for this AU is for a Jewish community to have formed in Atlantis pre-sinking. Sure, it requires some playing with the timetable of when said sinking happened, but it won't be the first story to do that so it's fine. They have deviated around the time of the 1st Temple's destruction, and are possibly mostly from the ten lost tribes of Israel. I don't have many more things to add, thank you to @cantotallyeven who thought this up! Maybe more details later.
Now, you might accuse me of certain hautiness in writing this. Please don't. Believe me when I say, I'm just enthusiastic about alternative Jewish histories, and would like to popularize the use of that tag. I would really like seeing farther AUs based on Jewish history - I had the pleasure to encounter a couple on Facebook, following a workshop on writing alternate Hannukahs in a meet-up organized by a group of interest on Jewish Fantasy in Israel. But there can be many more, and while I would love to contribute where I can and where my help is wanted, I prefer not to start any more than the one I'm already working on. So thank you to all the participants.
Note: the reblog chain for the Hasmonean Independence AU I shared here is only an exchange between me and Aviad. However, the 2nd Temple Still Standing thread includes (beside my and Magnetothemagnificent's posts) contributions from @alyssumlovesthecosmere and @fromchaostocosmos, hope you don't mind I'm tagging you as well.
