The Boston Molasses Disaster
The Rum Rebellion
. (It could be done as a sequel to a film about the Bounty
The Battle of Kadesh
. (Egyptians vs. Hittites; what's not to like.)
Hannibal's campaign against Rome.
The Fall of Rome in 476.
The Fall of Byzantium in 1453.
The Fall of Jerusalem in 587 BC.