The expedition began in 334 BC when Alexander crossed the Hellespont with an army of 35,000 men. He quickly defeated the Persian forces in several battles, including the Battle of Granicus and the Battle of Issus. By 331 BC, he had reached the Persian capital of Persepolis, which he burned to the ground. Alexander then continued his conquests, marching as far as India before turning back.
Alexander's expedition had a profound impact on the world. It led to the spread of Greek culture and philosophy throughout the Middle East and Asia, and it helped to create a more cosmopolitan and interconnected world. Alexander's conquests also laid the foundation for the Roman Empire, which would eventually become the dominant power in the Mediterranean world.