Gaugamela.
Alexander the Great decisively defeated the Persians led by Darius the Third at Gaugamela (located in Iraq) October 1, 331 BC .
There were several. The most decisive was Gaugamela.
I'm almost positive that he defeated the Persians at the Battle of Gaugamela.
Alexander the Great defeated Darius, king of Persia in 331 BCE. This was at the battle Gaugamela, he did march through Bactria in 329 BCE, but he had already defeated the Persians.
To decisively defeat enemy fleets at sea from their battle line.
At the battle of Marathon 490 BCE the Athenians defeated the Persians.
Figure it out
Notably , the battle of Marathon .
They did npt defeat Athens.
when he defeat the king darius 3
The sea battle of Salamis.
Figure it out