北地郡 / Beidi Commandery

Overview

北地郡 is a northern frontier commandery in accounts spanning Qin’s destruction of Yiqu, Qin Shi Huang’s post-unification journey, Liu Bang’s Chu-Han consolidation, and Han Wudi’s inspection of neglected defenses. Its recurrence shows how conquered frontier territory became an administrative and strategic inheritance whose infrastructure still required maintenance and accountable local government.

Current Profile

The commandery’s establishment, ritual-route role, Han occupation, and later defense failure are related but separate episodes. Hanji 350-2 adds a governance qualification to the territorial story: inheriting a frontier commandery and its strategic purpose did not guarantee that亭障 existed or remained effective. Wudi’s reported execution of the governor and implicated subordinates shows severe inspection-based accountability, while the exact scale and punishment remain source-scoped.

Key Characteristics

• Qin’s conquest of 义渠 culminated in the establishment of Beidi in 271 BCE after the Yiqu king’s killing at 甘泉宫.
• Together with 陇西郡 and 上郡, it formed a northern line for commandery administration, buffer management and defenses.
• It marked Qin Shi Huang’s western/northern old-Qin itinerary after unification in 220 BCE, which the host interprets as a ritual journey.
• In the Chu-Han struggle Liu Bang’s capture of Beidi after defeating Zhang Ping extended his Guanzhong frontier; later administration grouped it with Zhongdi and Longxi after Feiqiu fell.
• Under Han Wudi, an imperial inspection reportedly found roughly a thousand li in the Xinqinzhong area without亭障, leading to lethal punishment of the Beidi governor and responsible officials.

Evidence

• Conquest and institutionalization: The historical episode relates 宣太后’s decades-long Yiqu-king relationship, the king’s killing at Ganquan, Qin’s destruction of the leaderless polity, and creation of Beidi in 271 BCE, with Yiqu county as seat. It associates the old city with the modern Ning County/Qingyang, Gansu vicinity as a host-level geographic inference. 《资治通鉴·周纪》85｜宣太后为何私通30年后暗杀了老情人？
• Frontier system: Alongside Longxi and Shangjun, Beidi joined a connected northern defensive line and a basis for wall-building against northern Hu groups; control of Qin’s rear helped sustain eastward pressure. This is an interpretation of Qin Frontier Buffer Management / 秦国后方边患管理, not proof that the court planned every later defensive work at the moment of conquest. 《资治通鉴·周纪》85｜宣太后为何私通30年后暗杀了老情人？
• Imperial route: In 220 BCE the recorded itinerary runs from 咸阳 / Xianyang through Longxi and Beidi, via Jitou mountain and Huizhong. The episode reads the journey through old Qin lands as a possible High-Temple Rite / 高庙礼 toward 雍城 / Yongcheng (Qin), rather than ordinary sightseeing; the route itself does not establish that motive. 《资治通鉴·秦纪》121｜嬴政造世界最早高速公路 2200年荒草不生
• Han takeover and reorganization: A Chu-Han account has Liu Bang / 刘邦 take Longxi, attack Beidi and defeat 章平; the host describes the northern boundary reaching the Yellow River loop’s south bank and repairs to Qin-era frontier fortifications. Another account places Beidi with 中地郡 and Longxi in the administrative settlement after the year-long siege and flooding of 废丘, 章邯’s suicide and the pacification of former Yong territory. 《资治通鉴·汉纪》149｜西楚霸王项羽为何弑君（2） 《资治通鉴·汉纪》155-1｜历史记载什么情况会发生“人吃人”惨剧
• Defense maintenance and punishment: Hanji 350-2 says 汉武帝 rides north through Xiaoguan, inspects the Xinqinzhong frontier, finds a long stretch without defensive pavilions or barriers, and executes the Beidi governor and implicated officials. The branch shows infrastructure absence becoming personal administrative liability, but does not independently audit the distance, office list, or sentence.

Qualifications

• The sources describe Beidi’s Qin creation and a later Han administrative setup. They should not be flattened into a single founding event; the latter is a Conquest Commandery Transition / 灭国后的郡县化过渡 after regime change.
• Yiqu county as seat, the precise modern site, the motivation of 秦始皇’s journey, and details of frontier repairs are claims of the episodes rather than independently checked archaeological or court records. Xuan Taihou’s personal versus strategic motive is unresolved in the source.
• Hanji 350-2’s “千里无亭障” and collective execution language is retained as source-scoped. The episode does not separate never-built works from decayed or abandoned works, identify every punished subordinate, or test the proportionality of Wudi’s response.

What Changed

• The commandery’s Qin creation, imperial route and Han reuse are distinguished as successive frontier functions rather than source-arrival episodes.
• The geographic and ritual interpretations remain qualified rather than treated as settled fact.
• Added Han Wudi’s inspection to distinguish possession of frontier territory from maintained defensive capacity.

Relationships

• 秦国 / Qin State - conqueror of Yiqu; 芈八子 / 宣太后 / Xuan Taihou’s act at 甘泉宫 / Ganquan Palace precedes the commandery’s formation.
• 陇西郡 / Longxi Commandery - partner in both Qin frontier organization and Han post-conquest administration; 上郡 / Shangjun is a northern Qin defensive neighbor.
• Qin Eastward Pressure / 秦国东进压力 - rear security made eastern campaigns more viable in the historical episode’s reading.
• Qin Shi Huang / 秦始皇 - traveler through Beidi in the old-Qin itinerary toward the possible 雍城 / Yongcheng (Qin) ritual setting.
• Three Qin Containment / 三秦压制 - older frontier and Guanzhong military geography inherited by Liu Bang.
• 废丘 / Feiqiu - final former-Yong stronghold whose fall preceded a commandery reorganization.
• 汉武帝 - later inspector whose reported punishment makes Beidi a case of frontier infrastructure accountability.
• 治未病式边疆治理 - contrasting relationship showing the cost of waiting until an imperial inspection exposes absent defenses.