Agent of Byzantium
In the alternate medieval history Turtledove proposes, in this third novel in the Isaac Asimov Presents series, Muhammed's conversion to Christianityin lieu of founding Islamallows the Roman Empire to flourish and expand. This makes for a more peaceful, but also more static, age. Basil Agyros is an imperial commander of scouts in the latest barbarian skirmish when he proves his worth by retrieving the magical instrument with which the enemy divined Roman strategy at a distancea newly invented telescope. Promoted to bureaucrat in Constantinople, he acts as troubleshooter and 14th century scientific detective. The episodes betray their origin as separate stories and beg plausibility with Basil's stumbling on inventions from gunpowder to printing, but these intelligent, colorful tales honorably recall L. Sprague de Camp, the master of historical SF whom Turtledove invokes in his preface.