Persian king Darius III failed to appreciate tactics & lost his empire to this great leader in 331 B.C.
[DOC] [TLE] The Greek Empire (Bible History Online) [PAR] Alexander the Great, quickly and powerfully conquered the Persians in a brilliant 
series ... Alexander died in 321 BC, and after his death his empire was divided 
into four ... Syria and Mesopotamia, and defeated Darius again at Gaugamela (
331 B.C.E.).