Alexander the Great
Alexander the Great (Alexander III of Macedon), was a Macedonian king and general. He was a member of the Argead dynasty and son of the Macedonian king Philip II.
Shortly after inheriting the throne, he invaded the mighty Achaemenid Empire (a.k.a. Persian Empire) and let arguably the most successful military campaign of classical antiquity. Equipped with a seemingly invincible heavy infantry in the form of a phalanx, elite cavalry from Thessaly and siege equipment more advanced than anything the world had seen before, Alexander defeated armies much large than his own. He did this repeatedly and twice (in the Battle of Issus and Battle of Gaugamela) made the Persian king Darius himself flee in terror.
He progresses as far as to the borders of India, where he still managed to win his battles. Only the pressure of his army, exhausted by the long campaign far from home, stopped him from continuing even further. Alexander died young, aged only 33, and under suspicious circumstances. His vast empire was soon divided among his generals who spent the following decades in struggles for power.
Alexander's successful military career inspired many later kings and generals who listed him as their idol - e.g. Hannibal and Gaius Julius Caesar.