Alexander the Great and his physician Philippos. Alexander III of Macedon (356-323 BC), commonly known as Alexander the Great, was a Greek king of Macedon. Alexander was tutored by Aristotle until the age of 16. In 334 BC, he invaded Persian-ruled Asia Minor and began a series of campaigns that lasted ten years. Alexander broke the power of Persia in a series of decisive battles, overthrew the Persian King Darius III and conquered the entirety of the Persian Empire. Alexander had created one of the largest empires of the ancient world, stretching from the Ionian Sea to the Himalayas. He was undefeated in battle and is considered one of history's most successful commanders. Alexander's legacy extended beyond his military conquests. His campaigns greatly increased contacts and trade between East and West, and vast areas to the east were significantly exposed to Greek civilization and influence. Some of the cities he founded became major cultural centers, many surviving into the twenty-first century. In June 323 BC, Alexander died a painful death in the palace of Nebuchadnezzar II, in Babylon, at age 33. General consensus is he died of poisoning, but natural causes have been suggested: malaria, typhoid fever, acute pancreatitis, West Nile virus and possibly an overdose of medication containing hellebore, which is deadly in large doses.