Alexander the Great, a patient and often devious man; had never struck without careful planning. The youthful, headstrong Alexander liked to settle problems by immediate action. Making decisions with great speed, he took extraordinary risks; his success was achieved by the amount of sheer force and drive to overcome these risks. Alexander was educated as a student by the Greek philosopher Aristotle. The philosopher imbued Alexander with a love of Greek art and poetry, and instilled in him a lasting interest in Philosophy and science. .
Within a year of his accession, Alexander extended his dominions northward toward the Danube River and westward towards the Adriatic Sea. He then turned his attention to Greece where Thebes and Athens were threatening to bolt the league with weapons purchased with Persian gold. Also, Athens and Thebes were to unite in war against Macedon. In 335 B.C. Alexander decided to punish the city for what he regarded as treachery; .The city was destroyed and its people sold into slavery or killed. All of the city_s buildings were destroyed except for temples and the house of Pindar the poet. Pindar was long dead, but Alexander wanted to prove that even a Macedonian conqueror could be a Hellene. The savage lesson of Thebes brought results, the Athenian assembly quickly congratulated Alexander, and the Greek states, with Sparta as the continuing exception, remained Macedonian allies. .
Alexander now took on a project that Philip had planned but never carried out: an invasion of Persia. He decision to do this was purely a political one. For a century Persia had interfered increasingly in Greek affairs and had constantly oppressed the Greek cities in Asia Minor. Alexander had personal reasons too. Avid for glory and for identification with Greece, Alexander knew no better way to win both than by attacking Greece_s ancient foe. In some ways the invasion, the longest military campaign ever undertaken, was a reckless undertaking.