Not quite at the same scale, but Dan Simmons writes some pretty great alternate/fictionalized history that tend to be pretty lengthy (if that's your thing). I p

Not quite at the same scale, but Dan Simmons writes some pretty great alternate/fictionalized history that tend to be pretty lengthy (if that's your thing). I particularly enjoyed Drood and The Terror (from which the TV series was adapted), and Black Hills is pretty nice as well. He also did Hyperion Cantos and the Ilium/Olympos series if you're more into s-f.