What event marked the beginning of the Chinese's use of rockets in warfare?

The beginning of the Chinese use of rockets in warfare is closely associated with historical conflicts, particularly during the war with the Mongols. This period saw the development and deployment of various military technologies, including early forms of rocket artillery. The Mongolian invasions prompted the Chinese to innovate in their military strategies and weaponry, leading to the application of gunpowder-based rockets in combat.

While the invention of gunpowder laid the foundation for these advancements, it was the actual military engagements, specifically those with the Mongols, that catalyzed the integration of rocket technology into warfare. The bamboo rockets, although notable, were more of an early experimentation phase rather than a tactical deployment in battles. Lastly, the creation of a national space agency does not pertain to the historical context of rocket warfare but rather refers to contemporary advancements in aerospace technology. Thus, the conflict with the Mongols marks a significant event in the history of warfare that directly relates to the use of rockets in China.