This is one of those fantasy books that is inexplicably marketed with three vague lines basically everywhere, so have an actual dust jacket blurb up front:

Eadaz du Zāla uq-Nāra of the Priory of the Orange tree has been sent undercover to the far-away court of Inys to protect Queen Sabran Berethnet the Ninth in secret. Sabran, young and unwilling to marry, is suffering under the burdens of her office; to be not just the Queen of a country, but also the religious head of three countries, direct descendant of the saviour and founder of Virtuedom, living seal against an unspeakable evil and future mother of the next Berethnet. Sabrans and Eads shared close friend Arteloth Beck has recently disappeared; he and his friend Kit are on a mission to the draconic nation of Yscalin. In the East, Tané, a village orphan chosen by the gods, is fighting for her place in the Clan Miduchi, the famed sea fighters and dragon riders that protect Seiiki from pirates and evil firebreathers both. She crosses path with Sabran’s denounced, exiled and bereft former court alchemist who seeks the secret of eternal life. All of them live in the shadow of an era ending and an old threat to all humanity, the Nameless One, ruler of wyrms, rising once again.

Priory of the Orange Tree is a sprawling Pseudo-Arthuriana/Mythical Epic Fantasy novel with an appropriately fraught, clandestine courtly-chivalric love story and at its centre. It's over 800 pages long, so it take a while for anyone to actually kiss, and it plainly is a high fantasy, not a romance novel, so I wouldn't read it solely for any promised relationships.

Less formally, I described it over in my more in-depth review on my blog as having everything: giant evil dragons, good wise dragons, horse-girl dragon riders, lady knights, identity shenanigans, chivalric knights and dames, secret orders of lady fighters, lesbians with swords, pirate ladies, tragic romances, tragic bromances, non-tragic romances, secret romances, chivalric romances, ancient horrors and also a giant flying tsundere weasel.

My main complaints/(non-cw) caveats are that if you love Tané in the beginning ... well, she gets way less plot/page-time/attention than she deserves, which is a shame and secondly that despite being an 800+ page door stopper, a lot of locations and plot points did not get the breathing room they imo needed.

( Some content warnings )