Qin dynasty
Note: King Zhaoxiang of Qin (秦昭襄王) had already been ruling Qin for 51 years when Qin annihilated the Zhou dynasty; however the other six warring states were still independent regimes. Some Chinese historiographers thus used the next year (the 52nd year of King Zhaoxiang of Qin) as the official succession from the Zhou dynasty.
King Zhaoxiang of Qin
King Zhaoxiang reigned as the King of Qin for 57 years, and was responsible for the state of Qin achieving strategic dominance over the other six major states. During his reign, Qin captured the Chu capital Ying in 278 BC, conquered the Xirong state of Yiqu in 272 BC, slaughtered a 450,000-strong Zhao army at Changping in 260 BC, and overthrew the Eastern Zhou dynasty in 256 BC. These aggressive territorial expansions and the strategic weakening of other rival states paved the path for Qin's eventual unification of China three decades later by his great-grandson Ying Zheng.