King Zhaoxiang of Qin
Because King Zhaoxiang had not yet legally come of age (traditionally at the age of 20), his mother, who was now known as Queen Dowager Xuan, became the regent. She was supported by her brothers, Wei Ran and Mi Rong (羋戎), as well as two other sons, Prince Yi (公子悝) and Prince Fu (公子巿), the four of them collectively known as the "Four Nobles" (四貴).
Qin (state)
In 771 , the Marquess of Shen formed an alliance with the Zeng state and Quanrong nomads, and they attacked and captured the Zhou capital Haojing, killing King You of Zhou. Duke Xiang of Qin led his troops to escort King You's son King Ping of Zhou to Luoyi, where the new capital city of the Eastern Zhou Dynasty was established. In recognition of Duke Xiang's efforts, King Ping formally enfeoffed Duke Xiang as a feudal lord, and elevated Qin from an "attached state" (附庸, "fuyong") to a major vassal state. King Ping further promised to give Qin the land west of Qishan, the former heartland of Zhou, if Qin could expel the Rong tribes that were occupying the land. The future generations of the Qin rulers were encouraged by this promise, and they launched several military campaigns on the Rong, eventually expanding their territories to beyond the original lands lost by the Western Zhou Dynasty.