Baxter, Stephen. "Fate and The Fire-lance"
Divergence: 1071 CE
What if: A traveller from the East brought the secret of gunpowder from China to Constantinople, and in consequence the Byzantine Empire never fell.
Summary: In 1914 London, a Byzantine prince betrothed to a British princess is murdered, and the fate of Europe hangs in the balance.
Published: In Sideways in Crime: An Alternate Mystery Anthology (ed. Lou Anders), q.v.