I first discovered the writing of Paul Park back in the late 1980s reading his well regarded Starbridge Chronicles which comprise Soldiers of Paradise, Sugar Rain and The Cult of Loving Kindness. I recall being impressed with these books, and vaguely recollect that they had a touch of French Revolutionary history about them.
I wrote a review of The Roumanian Quartet on my Cat Politics Blog back in July last year.
I found it to be a highly original fantasy series. It is set in an alternate Roumania and has one of the most memorable villainesses in literature.
As Ian Sales has commented below, there is also Celestis AKA Coelestis. My copy appears to be unread, pristine in fact, so as an afterthought it is hereby entered. Note to self, read it next.
Severna Park, is not a writer you hear much about these days or maybe never. However, I do have a copy of her novel Hand of Prophecy which was reviewed on the SF Site way back in 1998. The book appears to be something of a rarity, judging by the prices for it on Amazon. And no, as far as I know she is no relation to Paul Park.