Alexander the Not-So-Great
Alexander the Great
Alexander III of Macedon is often called Alexander the Great as a result of his victory against the Persian Empire and his vast conquests. Alexander took over more territory than any general before him, and it was not until the Mongols that an empire would surpass the size of Alexander's empire.
This does not make Alexander the greatest general the world has ever seen. While he was certainly one of the bravest generals and one of the greatest commanders the world has ever seen it was because of the situation others put him in, not because of his own generalship.
The Macedonian Army
The Macedonian army was developed by Alexander's father, Philip II. Philip trained the Macedonian army during his wars with Greece. It was also under Philip that most of Greece was pacified and this paved the way for large-scale recruitment and financing. Phalanx warfare was an evolution of the hoplite warfare of Greece, and Philip made his soldiers the best in the world.
When Philip II was assassinated, Alexander assumed control of his father's army. He did not have to train or drill his army; he simply inherited it. Most of the world's greatest generals had to train their own troops. They developed some tactics that made them better than everyone else and that is why they became great.
Napoleon had to make his fortune with the worst of the French forces, the Army of Italy. He was given the troops that were meant to be a diversion and used them to overthrow Austrian hegemony in Italy. Scipio Africanus and Hannibal both had to train their armies from recruits and mercenaries for their campaigns. Alexander, on the other hand, was given a ready made army that would have served just as well with Philip II as their leader.
Alexander led the best-trained force in the ancient world, and his infantry were the heaviest, most disciplined soldiers the world had ever seen. It would not be until they met the Roman Legions that they would meet their match. The forces he went to face on the other hand were more a collection of men than an army.
Darius III led an army composed of soldiers from all over the Persian world. From the shores of Anatolia to Central Asia, all the peoples and tribes sent soldiers to fight for Darius. They spoke different languages and were generally poorly armed and armored. Only the chariot forces of the Persian Empire could be considered great weapons, and even they were useless against Macedonian phalanxes.
Alexander led an elite force supported by well armed and armored Greeks. He personally led the Companion Cavalry, who overwhelmed the Persians in every battle. Alexander had no special tactics or military designs. In every major battle Alexander won, Macedonian phalanxes marched in his center, while he led the Companion Cavalry along the enemies flank. Oftentimes he would simply lead a suicide charge against the enemy general who would then flee the field, such as in the Battle of Gaugamela, where the Persian Empire was defeated and collapsed.
This was Alexander's great strategy, he charged headlong at the enemy and killed them all in combat. When compared to the other great generals of the world it becomes laughable that Alexander is considered a great general, or a tactical master. Alexander was an amazing commander in that he personally led his cavalry and inspired his troops. His soldiers would have followed him on a charge into Hell, but the only reason he was so successful was that his enemies were so pitiful.
The Hellenistic Empire
Alexander the Great conquered one of the largest land empires in history, but that is all he did for his empire. By destroying the Persian Empire and usurping the royal practices of the Persian kings he just took the place of the Persian king. Furthermore, Alexander actually failed to pacify most of his empire. For these reasons, Alexander should be considered a poor administrator since he barely administered the empire.
After Alexander died, his successors had to spend several years making Alexander's conquests Macedonian. There were multiple tribes in Anatolia that Alexander simply bypassed and left sovereign in their own land. Alexander had co-opted the Persian satraps, but many rebelled upon his death. Most of the eastern territories broke away and created their own kingdom.
Many of Alexander's policies were failures. He had made his generals marry Persian women to integrate the Macedonians and Persians, but once he died many of his successors exiled, banished, or divorced their Persian wives. His attempts to create a unified Macedonian empire ended with his death when he failed to leave an heir to his empire.