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.