According to
The Secret History of the Mongols, the
yam was founded by
Ögedei Khan. Other sources show that a rudimentary postal system had already existed during the reign of
Genghis Khan.
The Secret History and some Persian sources credit Ögedei with installing post stations across the
Mongol Empire. As the Mongols expanded into northern China, the existing
Jin posts were incorporated into the
yam system. The
yam operated with a chain of relay stations at certain distances to each other, usually around apart. A messenger would arrive at a station and give his information to another messenger, and meanwhile rest and let the other messenger go on to the next station to hand the document to yet another messenger. This way information or documents were constantly on the move without each messenger getting tired. In each relay station, there would be spare horses, food, and shelter. The service has been described in great detail by European travelers including
Giovanni da Pian del Carpine,
William of Rubruck,
Marco Polo, and
Odoric of Pordenone. While it was not the first messenger system in history (earlier ones existed in the
Persian and
Roman Empires), it was unprecedented in size and efficiency. As the yam was constantly expanding, the Mongol war routes were transformed into commercial routes. People and messages could be sent from Korea to Persia or Mongolia to Vietnam through the use of horses or camel caravans. The Mongols replaced the old system of tax collection in Russia with a new one. After the death of
Alexander Nevsky in 1263, the new grand prince allowed the Novgorodians to organize their own system of tax collection, as long as payments to the Mongols continued. At first, the Mongols sent their own tax collectors. To keep Russian nobles on their side, although the nobles paid taxes, they were allowed to keep their lands and their authority in local politics was respected. Post roads with fixed stations were built after 1300 when the Mongols changed their method of having resident agents (known as
basqaq) to sending envoys whenever the tribute needed to be collected. ==Russian
yam==