In 221 BCE, Qi surrendered to Qin, ending the Warring States era and completing Qin’s rise from a western state to the unified imperial power that founded the Qin dynasty.
In 222 BCE, Qin completed the conquest of Yan and also extinguished Dai (a Zhao remnant established after Zhao’s fall), tightening Qin control over the northeast and removing remaining refuges for resistance.
Qin’s major invasion of Chu culminated in the capture of Chu’s capital and the state’s defeat by 223 BCE, eliminating the largest remaining territorial rival in the south.
In 225 BCE, Qin captured Wei’s capital Daliang—famously associated with a siege and flooding operation—leading to Wei’s surrender and shrinking the coalition of remaining states.
Qin forces took Handan and ended Zhao as a major independent power in 228 BCE, removing one of Qin’s most formidable northern rivals and further shifting the balance toward full unification.
In 230 BCE, Qin conquered Han, opening a rapid sequence of campaigns designed to dismantle remaining rival states one by one in accordance with Qin’s broader unification strategy.
In 238 BCE, Ying Zheng consolidated personal rule by eliminating major internal threats tied to court factionalism, clearing the way for centralized decision-making in Qin’s final drive toward conquering rival states.
After Ying Zheng formally acceded (246 BCE), Lü Buwei remained a central figure in Qin governance and state-building; his administration helped keep Qin’s expansion on track as unification became increasingly feasible.
Work on the Zhengguo Canal began in 246 BCE, expanding irrigated agriculture in the Guanzhong region and strengthening Qin’s logistical and grain base—an economic advantage that supported sustained campaigning.
Qin captured the remaining Eastern Zhou domain in 249 BCE, marking the final end of the Zhou dynasty’s surviving political structures and removing a lingering source of ritual legitimacy outside Qin control.
In 256 BCE, Qin conquered the West Zhou polity, a major symbolic blow to the already-fragmented Zhou royal house and an important step toward ending Zhou political remnants.
Zhao, aided by Wei and Chu, broke Qin’s siege of Handan (259–257 BCE). This setback temporarily checked Qin expansion and showed that coalition resistance could still succeed despite Qin’s growing power.
The Qin–Zhao campaign at Changping (262–260 BCE) ended in a decisive Qin victory (260 BCE), severely weakening Zhao and accelerating Qin’s path toward hegemony in north China.
Under King Zhaoxiang (reigned 306–251 BCE), Qin pursued sustained campaigns and diplomacy that gradually secured strategic superiority over rival states, making Qin the leading military power of the late Warring States era.
Qin’s conquest of Shu (316 BCE) brought new agricultural and manpower resources from the Sichuan Basin, strengthening Qin’s economic base and strategic depth for subsequent eastern wars.
After Duke Xiao died, Shang Yang lost protection at court and was executed (338 BCE). Despite his fall, Qin retained core Legalist institutions that underpinned later territorial expansion and state consolidation.
Upon succeeding Duke Xiao, Huiwen adopted the royal title (338 BCE), reflecting Qin’s growing autonomy and prestige within the weakening Zhou order and signaling Qin’s ambition to compete as a peer of other major states.
Shang Yang initiated a far-reaching reorganization of Qin administration and society—centralizing authority, tightening law enforcement, and emphasizing agriculture and military service—changes widely credited with transforming Qin into the strongest Warring States power.
Duke Xiao’s reign marked a decisive push to recruit talent and build state capacity in Qin, setting the political conditions for later Legalist reforms and sustained military expansion.
Rise of the State of Qin during the late Zhou (4th–3rd centuries BCE)
