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.
Marquis of Qin
Although Qin would eventually develop into a major power that would conquer all other Chinese states and unite China in 221 BC to start the Qin Dynasty, at the time of the Marquis of Qin it was still a minor state of the Western Zhou Dynasty classified as an "attached state" (附庸, "fuyong"). Qin rulers did not receive any nobility rank until four generations later during the reign of Duke Xiang of Qin, so "the Marquis of Qin" was presumably an honorific posthumous title that his descendants used to refer to him.