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).
Duke Xiang of Qin
In 771 BC King You of Zhou deposed Crown Prince Yijiu and made Bofu, the son of his favorite concubine Bao Si, the new crown prince. Yijiu was the son of Queen Shen who was the daughter of Marquis of Shen. Marquis of Shen rebelled at the news and made an alliance with the Quanrong tribe to attack the Zhou capital Haojing, killing King You at Mount Li. Marquis of Shen and other feudal rulers then installed Prince Yijiu on the Zhou throne as King Ping of Zhou. As Haojing was now ruined and still under the threat of the Quanrong, it was decided that the Zhou capital would be moved east to Luoyi, and Duke Xiang sent the Qin army to escort King Ping to Luoyi and established him at the new capital. This event marked the start of the Eastern Zhou Dynasty.