Alexander III of Macedon, called "the Great", was born approximately 356 BCE in Macedonian capital of Pella. His father was Philip II of Macedon, a king and military commander who had conquered much of the Balkan peninsula. His mother, Olympia of Epirus, was Philip's fourth wife. His tutor until the age of 16 was the famous philosopher, Aristotle. Two years later, in 338 BCE, Alexander led the Macedonian left at the Battle of Chaeronea, the battle which secured Macedonian hegemony over the Greek city states.
After his father's assassination in 336 BCE, Alexander became the king of Macedon. After securing his monarchy and rule over the Balkans and Greek city states, Alexander undertook his father's previously-planned invasion the Persian Empire. In 334 BCE, Alexander - with a force no less than 30,000 and no greater than 50,000 - crossed the Hellespont (the modern strait of Dardanelles) and landed in what is today Turkey. Over the next decade, Alexander conquered the entirety of the Persian Empire and added more territory besides. He remained undefeated in battle, earning him the moniker aniketos or "the Invicible" among his contempories. His most famous military feats in this campaign include the Battle of the Granicus River (334 BCE), the Battle of Issus (333 BCE), the Siege of Tyre (333 BCE), the Battle of Gaugamela (331 BCE), and the Battle of the Hydaspes River (326 BCE).
In 323 BCE, a few days shy of his 33rd birthday, Alexander died in Babylon of an unknown affliction (numerous theories exist, from tropical disease, to complications with previous wounds, to alcoholism). In less than a decade, he had solidified one of the largest empires in history, stretching from Greece and Egypt through the Middle East and into what is today Pakistan. His death resulted in decades of instability and military conflict between his immediate subordinates and their children, leading to the fracturing of the empire and the rise of several monarchic states known as the Successor Kingdoms, which held sway over much of the Mediterranean until they successively fell to Roman expansion.