Alexander the Great was the king of Macedonia or Ancient Greece. He is considered one of the greatest military commanders in history. When did Alexander the Great live? Alexander the Great was born on July 20, 356 BC. He died at the young age of 32 in 323 BC having accomplished much in his short life. He reigned as king from 336-323 BC. Alexander the Great by Gunnar Bach Pedersen Childhood of Alexander the Great Alexander's father was King Philip the II. Philip II had built up a strong and united empire in Ancient Greece, which Alexander inherited.After securing the throne and getting all of Greece under his control, Alexander turned east to conquer more of the civilized world. He moved swiftly using his military genius to win battle after battle conquering many peoples and rapidly expanding the Greek empire.Alexander only made it back to Babylon where he became suddenly sick and died. No one is sure what he died from, but many suspect poison. Upon his death the great empire he had built was divided up amongst his generals, called the Diadochi. The Diadochi ended up fighting each other for many years as the empire fell apart.