King Philip II of Macedonia conquered Greece in the 4th century BC, uniting the region under his rule. His son, Alexander the Great, then led Macedonian forces to invade Persia between 334-323 BC, defeating King Darius II and conquering the vast Persian Empire. Alexander established the city of Alexandria in Egypt and extended his empire as far as modern-day India before his death at age 32, leaving behind one of the largest empires in the ancient world and spreading Greek culture across his domains.