Database: Barid (Postal System)
Caliph al-Mansur believed that the Abbasid state stood on four pillars: clerics that feared God, guards that helped the weak, honest tax collectors ... and the barid, an extensive system of couriers and spies who ensured everyone else's loyalty!
Postal routes set up and paid for by the state have existed in one form or another in the Middle East since the Achaemenid Empire's Royal Road. It was an essential tool for ruling an empire stretching from Morocco to China. The Abbasids took over this system in 750 and expanded upon it in the following decades.
Their barid was made up of postal routes established to expedite the reception of news and the issuing of orders to the provinces. 930 small stations, 8 to 10 kilometers apart, were prepared and staffed with runners, riders, and horses ready to go at a moment's notice. Food, water, fodder, and everything needed by couriers were readily available to ensure the speedy transfer of information.
The head of the system was the sahib al-barid (master of letters). His job was to report the important affairs to the caliph, to carry out his orders, and to supervise the work of the empire's administrators. As such, he was respected by his colleagues as a man who could sway their whole destiny with a single word.