Okay, now for #2. After the Persians defeated the Greeks at Thermopylae, they proceeded towards Athens and burnt it to the ground. Themistocles convinced his people to flee by sea in the still-mighty Athenian navy, but it was a close thing. What if Themistocles had failed to convince his people to flee, and they had instead attempted to fight for their homeland? The move came as the result of a prophecy by an oracle saying that "wooden walls" would stop Persia, so they hide behind said walls. Athens, and the most powerful proponents of democracy, are killed as the Persians refuse to spare even the youngest and oldest Athenians.
How does this affect the world?