Final answer:
Persian emperors were unique in their time for their tolerance of local cultures and laws, upheld by an innovative system of governance that allowed conquered peoples to maintain their own practices under a benevolent rule.
Step-by-step explanation:
The unique aspect of Persian rulers during their era was their policy of tolerance towards local cultures and laws. The Achaemenid Empire was renowned for its multi-ethnic governance where the Persians not only respected the religious beliefs, languages, and political systems of the lands they conquered but also incorporated them into the administrative framework of the empire. This approach can be seen in the way they accepted Egyptian hieroglyphics and Babylonian record-keeping systems. Under the rule of Darius the Great and his successors, Persian kings allowed their subjects to maintain their traditions and practices as long as they remained loyal to the empire.
Part of this policy of tolerance involved a governing system where the empire was divided into Satrapies or provinces, each ruled by a Satrap, who was advised by a military general. These pairs of rulers were overseen by the 'eyes and ears of the king' who ensured the effective implementation of the king's commands throughout the vast territories. The Persians built an extensive network including the Royal Road, which greatly expedited communications across the empire. Furthermore, the Persian kings' image as benefactors was important to their authority, illustrated by actions such as Cyrus allowing the Jews to return to Judah.
In spite of the profound reverence and power attributed to the monarch, depicted as the 'King of Kings', the governance structure promoted a degree of autonomy among local rulers and practices, creating an innovative system of empire management which was subsequently admired and emulated by Alexander the Great after his conquest of the Persian Empire.