I highly recommend Anatolia Story/ Red River if you're looking for a shoujo series that has a strong main female character that goes through a ton of character growth + a historical setting. It's based after ancient Hittite/Mesopotamian mythology and features a bunch of real historical settings/figures which is really cool. It is for a more mature audience, though, as there's a lot of partial nudity, sexual situations, and implied scenes. There's also some attempted noncon and dubcon in a historical period kind of way that I feel the need to warn about, as well. Beautiful late 90s/early 2000s art, too. It's not /really/ a reverse harem though you have the same situation as you do with AnY, where pretty much all the characters are in some form of love and undying devotion with main female character (but also main male character, too. Major power couple lmao). It's VERY good and personally my favorite series. It was what turned me on to AnY, too.
I saw someone mention Reimei no Arcana and I can promise you that series is so not worth it. The pacing was awful and while the character development was there it was awkward and all of a sudden? Like a page flip and "bad" character had "changed his ways". I thought it was going to be reverse harem but it ended up just being an awkward love triangle and spoiler alert but one side of it was full blooded brother/sister incest, though you (and main female character) don't find out until the last chapter. The brother knew the whole time, though. That aside, the series set itself up to have been REALLY interesting but it only got so far on elaborating and then fell flat and ended. Poorly. I'm disappointed it was published in America because it was honestly just so... sad. Now every time I see it I'm forced to relive the fact that I read it.
There's also Himegimi to Sanbiki no Kemono if you want group of guys go on an adventure with a runaway princess. It touches on reverse harem-y but there's one obvious main romance. It's got a strong main female character, though, and three really handsome guys. I read it awhile ago and don't remember a whole lot but I know I enjoyed it for what it was and it's got a really sweet happy ending.
Sorry these are long. I've got a lot of feelings toward things, haha