Ford, John M. The Dragon Waiting: A Masque of History
Divergence: 331 CE
What if: Byzantine emperor Julian mandated religious tolerance in the empire and Justinian had time to consolidate his gains. Also, magic works.
Summary: A Welsh mage, Florentine doctor, German vampire and Greek mercenary become involved in England's Richard III's struggle for power.
Published: Simon & Schuster/Timescape 1983 (0671475525); SFBC 1984; Avon 1985 (0380698870BUY); and Gollancz 2002 (0575073780BUY).
Awards: Winner: 1984 World Fantasy Award for best novel.