商於 / Shangyu
商於 / Shangyu appears in 《资治通鉴·周纪》23丨魏惠王 悔不用公叔之言 as the Qin reward granted to 公孙鞅 / 商鞅 after the victory over 魏国. The episode says Qin gives him fifteen cities in the Shangyu region, making him 商君 and supplying the basis for the later Shang Yang name.
The page is source-scoped. Shangyu matters here because it converts 和谈诱捕 and the defeat of Wei into visible reward under 秦国’s 军功爵制-oriented political world. It later becomes the place where Shang Yang raises troops before being killed after fleeing back from Wei.
《资治通鉴·周纪》50丨张仪是怎样把楚怀王忽悠瘸的 reuses Shangyu in a very different Zhang Yi story. 张仪 promises 楚怀王 six hundred li of Shangyu if 楚国 cuts ties with 齐国, but after Chu breaks the alliance, he reduces the promised delivery to six li. This turns Shangyu from a real Qin reward in the Shang Yang branch into bait inside 未验地先断交陷阱.
《资治通鉴·周纪》51丨 楚怀王：秦小儿看舅舅如何灭了你！ makes that bait function visible through the aftermath. Once Chu fails to receive the promised Shangyu territory, Chu Huaiwang shifts from bargaining failure into angry retaliation, producing 丹阳之战, the loss of 汉中, and the later 蓝田之战 crisis. Shangyu therefore marks the point where a fake territorial promise becomes real military and diplomatic damage.
《资治通鉴·周纪》53丨秦惠王用张仪换地皮 brings Shangyu back as part of Qin’s proposed exchange for 黔中. The episode says 秦惠文王 offers land east of 武关 and around Shangyu, but 楚怀王 changes the bargain by demanding 张仪 instead. Shangyu therefore moves from promised bait in Zhouji 50 to one component of a territorial exchange that Chu uses to price revenge.
Connections
- 公孙鞅 / 商鞅 - recipient of the fief.
- 秦国 and 魏国 - rewarding state and defeated opponent.
- 军功爵制 and 耕战逻辑 - reward logic behind the fief.
- Qin Eastward Pressure / 秦国东进压力 - strategic field in which the victory is won.
- 作法自毙 - later death branch connected to Shang Yang’s return to the fief.
- 张仪, 楚怀王, and 未验地先断交陷阱 - Zhouji 50 promised-land deception branch.
- 丹阳之战, 汉中, 蓝田之战, and 忿兵决策 - Zhouji 51 aftermath of the failed Shangyu promise.
- 黔中, 武关, 可交换功臣, and 欲擒故纵式让利外交 - Zhouji 53 renewed land-exchange context.