Jin Zhentianlei (Heaven-Shaking Thunder Bomb)

Timeline

1. c. 1190–1210Northern Jin military production center · NortheastIn preparation for war against the Mongols, the Jin developed iron-cased explosive weapons, welding thin iron sheets into a shell filled with gunpowder and porcelain shards and iron filings; compared with bamboo and wooden weapons they had stronger fragmentation effects, and were called zhentianlei or leizhenpao, incorporated into city defense arsenals.
2. 1215Zhongdu city walls · North ChinaIn 1215 the Mongols besieged the Jin capital Zhongdu; Jin troops hurled or buried zhentianlei on the city walls and nearby, the explosions shaking heaven and earth and inflicting casualties on the Mongol besiegers, an important combat record of Jin city-defense explosives.
3. 1221Dexing Prefecture · HebeiIn 1221 the Mongols attacked Dexing Prefecture; the Jin again used zhentianlei to defend the city, and records describe the terrifying power of the iron shell bursting; though the city ultimately fell, the name of zhentianlei as the Jin's signature explosive weapon spread widely in Song and Yuan sources.