Tang Dynasty Crossbow Trigger Mechanisms

Timeline

1. c. 620–750Chang'an · ShaanxiUnder the Shaofu Jian and guard-commandery arms management system, early Tang crossbow triggers continued the bronze sight-scale and trigger structure; the Tang Liudian and Xin Tang Shu Bingzhi record multiple crossbow types, with acceptance standards for trigger material color, weight, and match to the stock.
2. c. 750–820Hexi and Longyou · Hexi CorridorIn the mid-to-late 8th century, the Hexi, Longyou, and Shuofang frontier commands widely equipped ambush and arm crossbows; both city defense and field battles relied on crossbow mechanisms for volley fire. Excavated Tang bronze triggers bear inscriptions or era dates, reflecting local arsenal casting alongside central allocation.
3. c. 820–900Central Plains regional commands · Central PlainsDuring 9th-century regional-command wars, crossbow mechanisms remained important for city defense and field battles. Crossbow methods cited in the Wujing Zongyao from before the Tang largely follow Tang practice: sight scales aid aiming, the trigger controls release, used together with large repeating devices such as bed crossbows and cart crossbows.