By share of population, the largest empire was the Achaemenid Empire, better known as the Persian Empire, which accounted for approximately 49.4 million of the world’s 112.4 million people in around 480 BC – an astonishing 44%. Originating in modern-day Iran, the empire was first established by Cyrus the Great and included parts of Central Asia, the Mediterranean, North Africa, and even European territories such as ancient Thrace and Macedonia.
Largest empire by percentage of world population
- Achaemenid Empire
- Not Applicable
- 480 BC