Alexander the Great from the workshop of Colin Nouailher, painted enamel on copper, partly gilt, 1541. Alexander III of Macedon (356-323 BC) was a Greek king. 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. He was undefeated in battle and is considered one of history's most successful commanders. 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. In June 323 BC, Alexander died a painful death in the palace of Nebuchadnezzar II, at age 33.