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 Xian of Qin (424–362 BC)
Duke Xian was the son of Duke Ling of Qin, the 25th ruler of the state of Qin. However, when Duke Ling died in 415 BC, the throne was passed to Duke Ling's uncle Duke Jian, instead of his son. Duke Jian reigned for 15 years and was succeeded by his son Duke Hui II, who died 13 years later in 387 BC, and was then succeeded by his son Chuzi II. As Chuzi was only a baby, the power was controlled by his mother, the duchess dowager. In 385 BC, the second year of Chuzi's reign, the minister Jun Gai (菌改) rebelled against Chuzi and the duchess. He led his force to escort Duke Xian, who was at the time exiled in the State of Wei, back to Qin, killed Chuzi and his mother, and installed Duke Xian on the throne.