函谷关 / Hangu Pass
函谷关 / Hangu Pass appears in 《资治通鉴·周纪》33丨历史第一爽文男主角苏秦 as the boundary marker in 《史记》’s claim about 苏秦’s 合纵 success: after the six-state alliance forms, Qin troops supposedly do not dare leave the pass for fifteen years.
The episode immediately makes that claim a source-critical problem. 《资治通鉴》 soon records 秦国 taking military action again and the six-state alliance falling apart, so Hangu Pass functions here less as a geography lesson than as the test point for legendary alliance efficacy.
《资治通鉴·周纪》34丨秦国总理如何玩转六国 supplies the promised test. Qin is again active from 332 to 328 BCE, disrupting the eastern alliance through 犀首公孙衍, taking and extracting territory from 魏国, and elevating 张仪. The pass therefore remains a marker of 《史记》’s stronger claim, not a description that fits this Zizhi Tongjian sequel literally.
《资治通鉴·周纪》45｜以史为鉴，君王到底该不该杀人成性？ gives the pass another anti-Qin test in 318 BCE. Five eastern states reach Hangu Pass under 楚怀王’s alliance leadership, but the army stalls because each state preserves its own strength. Qin cuts Chu’s supply route, Chu withdraws, and the coalition collapses, making the pass a marker for 联盟自保失灵 as well as source-critical hezong legend.
《资治通鉴·周纪》61丨谁是历史上胆儿最肥的帝王？ makes the pass a constraint to route around. After personally scouting 秦国 in disguise, 赵武灵王 judges that repeated eastern attacks on Qin struggle because Hangu Pass is too defensible. His alternative is to move from Yunzhong and Jiuyuan south toward 咸阳, turning the pass from a coalition-frontier marker into a problem for operational imagination.
Hanji 139 adds a late-Qin prisoner-security version. As 项羽 leads the anti-Qin coalition west with surrendered Qin troops, the pass becomes the imagined point where those troops might face Qin defenders, rebel, or rejoin Qin. That fear is part of the episode’s rationale for 新安坑降 before the coalition reaches the Qin heartland.
Hanji 140 part 1 changes the pass problem from surrendered-Qin security to Liu Bang/Xiang Yu rivalry. 刘邦 seals the Guanzhong entry route after reaching the region first, and Xiang Yu sends 英布 and others to break through. The pass therefore becomes the material boundary where the 怀王之约 reward race turns into open coercion among former anti-Qin allies.
Connections
- 秦国 - state whose eastward military movement is being described.
- 苏秦 and 合纵 - strategist and alliance whose claimed success is measured by Qin not crossing the pass.
- 《史记》, 《资治通鉴》, and 编年错位 - source tension around the fifteen-year claim.
- 纵横家外交 - broader Warring States diplomatic field in which the pass becomes political evidence.
- 楚怀王, 合纵, and 联盟自保失灵 - Zhouji 45 five-state attack and withdrawal branch.
- 赵武灵王, 秦昭襄王, 咸阳, and 战国军事形态转变 - Zhouji 61 bypass strategy after disguised reconnaissance.
- Hanji 139, 项羽, 新安坑降, 章邯, and 杀降安全困境 - feared mutiny or reattachment point for surrendered Qin troops.
- Hanji 140 part 1, 刘邦, 英布, 关中, and 鸿门宴 - closed entry route and forced breakthrough before the banquet crisis.