华阳之战 / Battle of Huayang
华阳之战 / Battle of Huayang enters the wiki through 《资治通鉴·周纪》83丨诸侯摆烂竟成了经典计中计？ as the campaign in which 魏国 and 赵国 attack 韩国’s Huayang, a northern gate of the Han capital region near Xinzheng. The episode places the attack after 魏安釐王 has already been humiliated by Qin and reads it as Wei seeking a victory against a weaker neighbor after failing to withstand 秦国.
Han’s response turns the battle into a diplomatic case as much as a military one. Rather than simply offering land for rescue, the Han envoy implies to 魏冉 that if Han becomes truly desperate it can surrender to the Wei-Zhao side. That 投敌威胁式求援 makes Qin see rescue as a way to prevent its rivals from absorbing Han.
Qin moves quickly. Wei Ran, 白起, and the Qin guest minister Hu Yang reach Huayang after an eight-day forced march, defeat Wei, force 芒卯 to flee, capture three Wei generals, and inflict the episode’s reported 130,000 Wei casualties. Bai Qi then fights the Zhao commander Jia Yan, with the episode preserving uncertainty about how the reported drowning of 20,000 Zhao troops in the Yellow River occurred.
For the wiki, Huayang is a hinge between 秦国东进压力 and 战国同盟转向. A war started by Wei and Zhao to exploit Han instead tightens Qin’s control over the central-plains states and pushes the later debate over 抱薪救火式割地求和.