盖延 / Gai Yan (Eastern Han)

Overview

Gai Yan / 盖延 enters the wiki through Hanji 690 as the Eastern Han commander whose Lanling response illustrates failed indirect relief. When 董宪 surrounds Lanling after Ben Xiu offers the county to Han, 光武帝刘秀 tells Gai Yan to attack Tan so the Lanling siege will lift. Gai Yan instead rushes to the besieged city, enters after Dong Xian feigns retreat, then breaks out in fear and fails to save Ben Xiu.

Current Profile

The source gives Gai Yan a compact but clear command problem. His instinct is direct rescue: Lanling is in danger, so he wants to move toward Lanling. Liu Xiu’s answer is indirect pressure: strike Dong Xian’s own base at Tan and the besieger will be forced to leave.

Gai Yan’s failure comes from choosing the urgent visible site over the must-save site. Dong Xian’s feigned retreat lets him enter Lanling, but the next day’s encirclement changes the rescue into a trap. Gai Yan breaks out, then goes toward Tan too late. Liu Xiu’s rebuke frames the lesson: the indirect strike mattered before Dong Xian’s plan settled, not after Lanling had been re-enclosed.

Key Characteristics

• Eastern Han commander in the Jianwu 4 Dong Xian/Lanling branch.
• Direct-rescue actor who overrides Liu Xiu’s indirect-relief instruction.
• Commander deceived by Dong Xian’s feigned retreat into entering a vulnerable city.
• Negative case for tactical urgency outrunning strategic target selection.
• Figure whose failure leads to Lanling’s fall and Ben Xiu’s death.

Evidence

• Direct rescue request: Hanji 690 says Gai Yan and Pang Meng ask to go rescue Ben Xiu at Lanling.
• Liu Xiu’s instruction: Hanji 690 says Liu Xiu tells them to attack Tan directly so the Lanling siege will dissolve.
• Failed execution: Hanji 690 says Gai Yan goes to Lanling anyway, enters after Dong Xian feigns defeat, then flees after being surrounded.
• Outcome: Hanji 690 says Gai Yan later cannot take Tan and Dong Xian captures Lanling and kills Ben Xiu.

Qualifications

This page does not reconstruct Gai Yan’s full Eastern Han career. Pang Meng, Ben Xiu, Tan/Lanling geography, and exact force dispositions remain source-scoped. The current evidence supports a negative command lesson in this episode, not a final judgment on all of Gai Yan’s service.

What Changed

• Created Gai Yan as the Lanling negative case for ignoring indirect-relief strategy.

Relationships

• 光武帝刘秀 - ruler whose indirect-relief instruction Gai Yan does not follow.
• 董宪 - opponent whose feigned retreat and renewed encirclement defeat Gai Yan’s rescue.
• 围魏救赵 - strategy pattern Gai Yan fails to apply at Lanling.
• 声东击西与诱敌 - related because Dong Xian uses feigned retreat to pull Gai Yan into a worse position.
• 行势情战略评估 - related because the case turns on reading target, timing, and enemy compulsion together.