Alexander was born to a wealthy noble family. He had several half brothers and sisters who had various different mothers. His father, Philip, was the king of Macedonia. Philip was a great leader and a brilliant strategist with a dream of defeating Persia. Alexander's mother was Olympias, the princess of Epirus and the fourth wife of Philip. Because Alexander was half-Greek, many questioned whether he should be able to rule.
During his childhood, Alexander was tutored by the philosophist Aristotle. Aristotle taught Alexander everything he knew about Greece. When Alexander wasn't being tutored, he probably fantasized about leading an army into battle. He had always been transfixed by his father's army and could not wait to rule. When he was around 12 years old, Alexander tamed a horse which no one else could tame. From then on, he had a deep bond with his horse (Bucephalus) and even named a city after it. Another horse that Alexander loved was the Trojan horse. Alexander was entranced by the Epics of Homer and enjoyed them even as an adult. His favorite story was the Illiad; which he was said to have carried with him everywhere.
When Alexander was around 20, his father was murdered; this left Alexander to be king of Macedonia. He, like his father, wanted to conquer Persia and be the leader of all of Greece. However, Alexander could never be satisfied with his power. Alexander conquered and founded lands that no Greek had ever ventured into. The only thing that stopped him from continuing on were his troops. When they reached the Indus River, Alexander's men refused to go any further. When they returned to Macedonia, Alexander married the princess of Persia in order to keep his empire united. He also ordered his men to marry Persian women.
By the time Alexander and his army turned back, he had already conquered and discovered two million square miles of land. He also founded over 70 cities which he named after himself, his horse, and anything else that was dear to him. While his empire was his most memorable achievment, he had a few other notable accomplishments. One interesting accomplishment was that he was crowned a pharaoh. The Egyptians praised him for removing them from Persian rule and made him their pharaoh. Another interesting accomplishment was that he actually did defeat the Persians. As a symbol of this, he burned down the Persian capital, Persepolis.