Phillip II of Macedonia conquered Greek city-states and defeated them at the Battle of Chaeronea in 338BC. His son, Alexander the Great, then invaded Asia Minor in 334BC and over the next few years, he conquered the Persian Empire and expanded all the way to India. However, exhausted from constant battles, Alexander's troops demanded to return home. Alexander died of a fever in Babylon at the age of 32 in 323BC, before he could return to Macedonia.