The Element of Fire, by Martha Wells, Tor, 1993.
After reading one of Wells' books about Ile-Rein I went search for others. It turns out that Wells has written a number of books about about Ile-Rein at various points during its history. The Element of Fire is set during Ile-Rein's era of muskets and swords, and is a very good mixture of swashbuckling and magic. I look forward to reading more of Wells' works.