Alexander III of Macedon (20/21 July 356 – 10/11 June 323 BCE), commonly known as Alexander the Great, is a Greek king of Macedon, a state in northern ancient Greece.

Born in Pella in 356 BCE, Alexander is tutored by Aristotle until the age of 16.

By the age of thirty, he has created one of the largest empires of the ancient world, stretching from the Ionian Sea to the Himalayas.

He is undefeated in battle and is considered one of history's most successful commanders.

Alexander succeeds his father, Philip II of Macedon, to the throne in 336 BCE after Philip is assassinated.

Upon Philip's death, Alexander inherits a strong kingdom and an experienced army.

He is awarded the generalship of Greece and uses this authority to launch his father's military expansion plans.

In 334 BCE, he invades Persian-ruled Asia Minor and begins a series of campaigns that lasts ten years.

Alexander breaks the power of Persia in a series of decisive battles, most notably the battles of Issus and Gaugamela.

He subsequently overthrows the Persian King Darius III and conquers the entirety of the Persian Empire.

At this point, his empire stretches from the Adriatic Sea to the Indus River.

Seeking to reach the "ends of the world and the Great Outer Sea", he invades India in 326 BCE, but is eventually forced to turn back at the demand of his troops.

Alexander dies in Babylon in 323 BCE, without executing a series of planned campaigns that would have begun with an invasion of Arabia.

In the years following his death, a series of civil wars tear his empire apart, resulting in several states ruled by the Diadochi, Alexander's surviving generals and heirs.

Alexander's legacy includes the cultural diffusion his conquests engendered.

He founded some twenty cities that bore his name, most notably Alexandria in Egypt.

Alexander's settlement of Greek colonists and the resulting spread of Greek culture in the east resulted in a new Hellenistic civilization, aspects of which were still evident in the traditions of the Byzantine Empire in the mid-15th century.

Alexander became legendary as a classical hero in the mold of Achilles, and he features prominently in the history and myth of Greek and non-Greek cultures.

He became the measure against which military leaders compared themselves, and military academies throughout the world still teach his tactics.