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.

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.