His dreams were fulfilled , and even surpassed , by his son Alexander the Great , in a brief but action-filled lifetime of only 33 years ( 356 323 b.c. ) . In 334 b.c. , aged only 22 , he led his army across the Hellespont ( now the Dardanelles ) , and paused at Troy to make a sacrifice at the temple of Athena and pay homage to his hero Achilles , before going on to defeat the Persians at the Battle of Granicus and liberating the Ionian cities .
The Ionian cities were freed after Alexander the Great defeated the Persians at Granicus .