Multistage rocket
TL;DR
Multistage rocket - requires enrichment with adjacent possible narrative
An illustration and description in the 14th century Chinese Huolongjing by Jiao Yu and Liu Bowen shows the oldest known multistage rocket; this was the "fire-dragon issuing from the water" (火龙出水, huǒ lóng chū shuǐ), which was used mostly by the Chinese navy.
What Had To Exist First
Preceding Inventions
Biological Patterns
Mechanisms that explain how this invention emerged and spread: