Baker, Kage. "Silent Leonardo"
Divergence: c 1467 CE
What if: Leonardo da Vinci had a partner who made sure his inventions were transmitted from paper drawings to actual construction.
Summary: Leonardo's designs for a great siege engine and man-carrying gliders are put to bloody use.
Published: In ReVisions (eds. Julie E. Czernada and Isaac Szpindel), q.v.