Timeline of postal history
This is a partial timeline of significant events in postal history, including dates and events relating to postage stamps. == 559–530 BC == Chapar Khaneh, the state-run courier (and transportation) service of the Persian Empire was established by Cyrus the Great, and later developed by Darius the Great as the royal method of communication throughout the empire.
Source: Wikipedia — Timeline of postal history (CC BY-SA 4.0)