On Alexander's accession to the throne of his father, Philip II of Macedonia, he crushed a rebellion in Thebes, destroying the city and selling the entire population into slavery. He then set out to expand the Macedonian empire and control the world. By 334 BC he had defeated the Persians. Soon he ruled all the territory west of the Euphrates. Next he conquered Egypt, where in 332 BC he founded the great port city of Alexandria on the Nile Delta. Marching back into Mesopotamia, he entered Babylon, and made sacrifice to the local god, Marduk. Then he marched on Persepolis and burned it, seizing its royal treasury.
Convinced that India was small, and that beyond it lay Ocean, as he called it, by which route he could return to Europe by sea, he set out to conquer present-day Pakistan. His troops were exhausted, however, and met unexpected resistance in the form of war elephants; Alexander was thus forced to sail down the Indus River to the Indian Ocean. Returning finally to Babylon in 323 BC, Alexander caught a fever and died. By this time, the extent of his empire measured over 3,500 miles west to east.