Achaemenid Persian Empire

The Achaemenid Persian Empire under Darius I (522-486 BC) was the world's first superpower, spanning 5.5 million square kilometres from the Balkans to the Indus Valley and ruling an estimated 44% of the world's population at its peak — the highest percentage of global population ever controlled by a single empire in history. It pioneered the concepts of human rights, postal systems, and multicultural governance.