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.
Eastern Zhou
The Warring States period was an era in ancient Chinese history following the Spring and Autumn period and concluding with the Qin wars of conquest that saw the annexation of all other contender states, which ultimately led to the Qin state's victory in 221 BCE as the first unified Chinese empire known as the Qin dynasty.