I recently read Jack Weatherford's excellent book Genghis Khan and the Making of the Modern World. In it, he asserts that the trade network established by the Mongol empire was brought together the technologies of Europe, the Byzantine Empire, and China, which then made possible the invention of the cannon. However, did between those areas preexist the Mongols? Is the Mongol trade network really the primary cause for the cannon's invention?
(If you think you've seen this before, it's because I didn't receive any responses last time so I'm tryin' again!)
It's indisputable that the Mongol Empire had some role in the spread of the cannon and other gunpowder empire. However, the question of whether this was a direct or indirect transmission of the technology is still unsettled. Historians who favor the direct transmission theory believe that the Mongols were responsible for spreading gunpowder technology through their conquests in the Middle East and Eastern Europe. Historians who argue for indirect transmission believe that the gunpowder was transferred through trade networks during Pax Mongolica (Mongol peace), but not necessarily by the Mongols (May 2012).
But in order to proceed with this question, let's first discuss what most historians can agree on.
There is a large body of evidence that the Mongols used gunpowder weapons in East Asia. Fragments of Mongol bombs have been found off the coast of Japan. Various cannons have been excavated dating back to the Yuan period, with the earliest from the 13th century century and possibly earlier (Haw 2013).
The Mongols acquired gunpowder technology from the Jin dynasty in northern China. Former Jin engineers and soldiers were recruited by the Mongols into their army. Genghis Khan was likely aware of gunpowder through their interactions with the Jin (Haw 2013). Chinese engineers accompanied the Mongols to the Middle East.
The first description of gunpowder comes from a 9th century Chinese Taoist text. The earliest surviving recipe for gunpowder appears in a Song dynasty military test written in 1040 (Chase 2003). There are several references to gunpowder in Chinese historical records.
Now let's move on to the areas that are still under dispute. Whereas a large amount of archaeological, literary, and artistic evidence shows that the Mongols were using cannons in East Asia, the evidence for Mongol cannons in Europe or the Middle East comes strictly from the works of chroniclers. The names for Mongol weapons in the chronicles are ambiguous, leaving them open to interpretation. A Polish chronicler reports that the Mongol weapons were "the arts of divination and witchcraft" and Persian sources mention fire weapons.
There are some historians who believe that these textual references sufficiently prove that the Mongols were using gunpowder weapons in their campaigns in the west. However, May believes that the incendiary weapons used by the Mongols did not necessarily require gunpowder. Naptha was also available in the Middle East, and had been used for centuries (May 2012). And unlike in China or Japan, no surviving Mongol cannons or bombs have-as of yet-been excavated in the Middle East or Europe.
It's possible that East Asian cannons influenced later Western cannons. Military historians have observed how the vase-like shape of the earliest sculpture of a Chinese cannon visually resembles the earliest European illustration of cannon (Park 2005). However, without definite material evidence, the direct transmission of the cannon by the Mongols remains open for debate.
Sources:
Haw, Stephen G. "The Mongol Empire – the First ‘gunpowder Empire’?" Journal of the Royal Asiatic Society 23.03 (2013): 441-69.
May, Timothy Michael. The Mongol Conquests in World History. London: Reaktion, 2012.
Chase, Kenneth Warren. Firearms: A Global History to 1700. Cambridge, UK: Cambridge University Press, 2003.
Parker, Geoffrey. The Cambridge Illustrated History of Warfare: The Triumph of the West. Cambridge: Cambridge University Press, 1995.