东胡 / Donghu
东胡 / Donghu enters the wiki through 《资治通鉴·秦纪》114-3｜荆轲刺秦为何久久不行动？在等谁？ as the northern frontier opponent defeated by 秦开 in the episode’s background note on 秦武阳. The source says Qin Kai had once been a hostage among northern Hu peoples, then returned to 燕国 and forced Donghu back more than a thousand li.
Hanji 175 turns Donghu from a background frontier memory into the first major victim of 冒顿单于’s steppe consolidation. The source says Donghu asks first for Touman’s prized horse and then for one of Modu’s wives; Modu yields both, making Donghu assume Xiongnu fear. When Donghu next demands a large empty borderland, Modu treats land as a state root, kills advisers willing to give it away, and attacks before Donghu is prepared.
This episode therefore gives Donghu a structural role in the Xiongnu branch. Its overconfidence is the condition Modu exploits, and its destruction clears space for the stronger Xiongnu frontier pressure that soon reaches early 西汉.