My favorite historical “what-ifs” don’t depend on time-travel:
1. What if Anthemius of Trallus, one of Justinian’s engineers in the construction of the Hagia Sophia had actually developed his use of steam power for more practical uses than annoying his neighbor with simulated earthquakes? He is credited by some with having done this by means of a primitive reciprocating steam engine (albeit without a governor).
and (even more obscure)
2. What if Otto III had lived a long life with his intended bride?
What if Ogatai Khan didn’t die in the winter of 1241, and Sabotai and the Princes continued the conquest of Europe?
Wow, I learned something about a period of history that I absolutely love. He did an amazing amount in just 6 short years and was just 22. Gosh. What could have been, indeed.
One of my “what-ifs” is if Julius Caesar’s daughter, Julia, had not died birthing Pompey Magnus’ son?
First, the schism between Pompey and Caesar would not have happened and, thus, no “Crossing the Rubicon” Civil War.
Second...can you imagine a rightful heir with the blood of Caesar and Pompey running through his veins?
Interesting - I was waiting for someone to bring up the Byzantines. I always wondered what would have happened if Constantine XI had a couple machine guns or even a good sniper with rifle in 1483.
The Turks would have been finished and the M.E. would be a very different place today.
What if Robert E Lee had adopted the Gatling Gun after Gettysburg?