1. he launched the Persians’ imperial venture and was a tough leader and a great military strategist. In 558 BCE Cyrus became the king of the Persian tribes, and in 553 BCE he initiated a rebellion against his median overlord whom he defeated within three years.
2. His empire was the largest empire the world had seen. Governing a far-flung empire was much more difficult than conquering it. His empire presided over more than seventy distinct ethnic groups, including peoples who lived in widely scattered regions, spoke many different languages, and had many religions and traditions
3. The administration was centralized. The capital, Persepolis, served as an administrative center. Persepolis was home to advisors, ministers, diplomats, scribes, accountants, translators, and bureaucratic officers of all descriptions.
4. Darius standardized the coins which fostered trade throughout his empire. The Achaemenid empire built great roads across their realm, notably the so-called Persian Royal Road that stretched 2,575 km from the Aegean port of Ephesus to Sardis in Anatolia. Parts of the road were paved in stone. It took caravans 90 days to travel the road.
5. Alexander the Great defeated the empire with a well-disciplined army. His army carried heavier arms and used more sophisticated military tactics than the Achaemenids. This allowed Alexander’s army to easily defeat the Persian empire. After defeating the kit empire he claimed himself heir to the Achaemenid rulers and then set the capital on fire. Alexander portrayed himself in Persia and Egypt as a legitimate successor of the Achaemenids who observed their precedents and deserved their honors. He kept the Achaemenid administrative structure, and he even approved appointments of many satraps and other officials.
6. They established themselves