Explain why the Persians managed to keep their country from disintegration.

The Persian state at one time was very powerful and huge. Its territories stretched from the Indus River in the east to the Balkan Peninsula in the east. During the reign of Tsar Darius 1, the question arose about the effective management of the state. Thus, an administrative reform was carried out. In this connection, the entire empire was divided into 20 satrapies, each of which was ruled by a local governor – a satrap. Also, each satrapy had a small army to settle the unrest.