By 1234, Ögödei had won control of northern China and was on the verge of attacking the Southern Song. A couple years later, Genghis Khan 's grandson, Batu, conquered Russian territories including, Moscow, Hungary, and Poland. It was only Ögödei 's death that saved Europe from further attacks. However, in the Middle East, a Mongol army terminated the Abbasid caliph and conquered Baghdad.
Each area annexed brought foreign engineers and scholars into the empire which encompassed the Silk Road and with each conquest came the opportunity to control tax and tribute. Through each expansion, the Mongol Empire became more economically and technologically advanced. This period in which the Mongols controlled most of Asia became known as the Pax Mongolica. During the Pax Mongolica, the territory of the Mongol empire became a safe place where commerce and capitalism flourished. The Mongols re-established the Silk Road as a place where Europeans and Eurasian civilizations can travel safely and peacefully on well-maintained