Who Persian leader conquered the most territory?

Cyrus the Great is the Persian leader known for conquering the most territory. He founded the Achaemenid Empire and expanded it through military conquests across a vast region, including parts of modern-day Iran, Turkey, Egypt, and Central Asia. His innovative approach to governance and respect for local customs helped him maintain control over this diverse empire. Cyrus's conquests laid the foundation for one of the largest empires in history.