The rapid expansion of the Mongol Empire in the thirteenth century cannot be attributed to a single new military invention providing technological supremacy over their enemies. The weaponry and equipment of the Mongols differed little from those of their enemies or from previous nomadic empires. Still, the Mongols were adept in employing the tools of their foes. As historian Timothy May wrote, “the Mongols rarely met a weapon they did not like.” Therefore, many questions have been raised regarding the usage, or lack thereof, of gunpowder weapons in Mongolian expansion, particularly outside of China. Today, we give a brief introduction to gunpowder weapons, both their history of use, their use by the Mongols, and the possible role of the Mongol Empire in the dissemination of these weapons. I’m your host David, and this is Kings and Generals: Ages of Conquest.   For some historians, like J.J. Saunders or Kate Raphael, the Mongols as both users of gunpowder and transmitters of its knowledge to the west is a total negative or extremely unlikely. They see no clear indication of it’s usage in the western historical sources, seeing possible mentions as too equivocal to be relied upon. But the great British sinologist Joseph Needham and his associates, after a thorough study of well over a millennium of Chinese written sources and archaeology, has demonstrated thoroughly that not only were a number of a gunpowder weapons a common feature of Chinese warfare by the thirteenth century, but that the Mongols also used these during their wars in China. More recent historians such as Iqtidar Alam Khan, Thomas T. Allsen and Stephen G. Haw, have advanced Needham’s arguments, arguing that the Mongols carried gunpowder weapons, such as bombs, fire-lances and rockets, west in their conquests over the rest of Eurasia. Stephen Haw in particular has suggested that the infamous smoke-screen employed by the Mongols in Poland at the battle of Liegnitz in 1241 was a gunpowder-based weapon.    To demonstrate this, we must very briefly give an introduction to Chinese usage of gunpowder. Chinese alchemists and engineers had been mixing various chemicals for medicinal and experimental purposes for centuries, including some of those which constitute gunpowder. Gunpowder itself was not the result of any single individual’s experiments, in the style of the old European fable of Berthold Schwarz, but rather a long series of trials combining materials -often, rather ironically, in search of elixirs to eternal life- which ultimately resulted in discovering a rather flammable substance. The first recipe for gunpowder finally appears during the Tang Dynasty in the 8th century CE, in a Taoist work urging alchemists not to mix saltpetre (potassium nitrate), sulphur and carbon-rich materials like coal, and to especially not add arsenic to the mixture, as the result would light aflame. The Chinese quickly found the energy produced by these materials quite mesmerizing when used in fireworks display, and found use for it in civil engineering and mining,  but contrary to some popular sentiments that the Chinese only used it for peaceful purposes, it appears they rather quickly applied this new material for warfare. From the 10th century to the 13th, the Chinese created a great number of weapons to violently disseminate knowledge of gunpowder. By 1044, possibly in reaction to military defeats against the newly established Tangut ruled Xi Xia Dynasty, the Song Dynasty was presented a collection of nine kinds of gunpowder weapons and three distinct gunpowder recipes in the Wujing Zongyao. This technology advanced under the Song Dynasty, which faced a collection of ever-more fearsome foes on its northern borders.   From the 10th century onwards, these weapons took a number of forms.  Bombs thrown from catapults (huopao), enclosed in pottery or fragmenting metal shells. Arrows (huojian) with incendiary packages strapped to them, launched from bows or massive mounted crossbows,