King Zhaoxiang of Qin
In 293 BC, East Zhou decided to ally itself with the states of Han and Wei, and sent troops to help attacking Qin. However, the combined forces of this alliance was destroyed at Yique by the young Qin general Bai Qi, with 240,000 men killed and their commander Gongsun Xi (公孫喜) captured and executed. After this loss, the East Zhou was unable to actively participate in future interstate struggles in any significant fashion.
In 256 BC, Duke Wu of West Zhou (西周武公) allied with other states to stop the Qin offensive on the Han city of Yangcheng. In retaliation, King Zhaoxiang of Qin sent general Jiu to invade West Zhou, successfully breaking into Wangcheng. The Duke Wu was taken to Xianyang to beg for mercy, conceding all his lands. Both King Nan and Duke Wu would die later that year, and the subsequent Duke of West Zhou, Duke Wen (西周文公), was exiled to Danhuju (憚狐聚). Because the Zhou royal court had fallen from power and King Nan had died without a successor, the Eastern Zhou Dynasty collapsed, ending 879 years of Zhou monarchy. The remaining East Zhou state was also conquered by Qin chancellor Lü Buwei seven years later in 249 BC during the reign of King Zhaoxiang's grandson King Zhuangxiang, after Duke Jing of East Zhou attempted to form an anti-Qin alliance with other states.
Manchukuo
The Qing dynasty, which replaced the Shun and Ming dynasties in China, was founded by Manchus from Manchuria (modern Northeast China). The Manchu emperors separated their homeland in Jilin and Heilongjiang from the Han Liaoning province with the Willow Palisade. This ethnic division continued until the Qing dynasty encouraged massive immigration of Han in the 19th century during Chuang Guandong to prevent the Russians from seizing the area from the Qing. After conquering the Ming, the Qing identified their state as "China" (中國, Zhongguo; "Central Realm") and referred to it as "Dulimbai Gurun" in Manchu. The Qing equated the lands of the Qing state (including present day Manchuria, Xinjiang, Mongolia, Tibet and other areas) as "China" in both the Chinese and Manchu languages, defining China as a multi-ethnic state, rejecting the idea that China only meant Han areas, proclaiming that both Han and non-Han peoples were part of "China", using "China" to refer to the Qing in official documents, international treaties, and foreign affairs, and the "Chinese language" (Dulimbai gurun i bithe) referred to Chinese, Manchu, and Mongol languages, and the term "Chinese people" (中國人 Zhongguo ren; Manchu: Dulimbai gurun i niyalma) referred to all Han, Manchus, and Mongol subjects of the Qing. The lands in Manchuria were explicitly stated by the Qing to belong to "China" (Zhongguo, Dulimbai gurun) in Qing edicts and in the Treaty of Nerchinsk.