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).
Yao Xing
Yao Xing was born in 366, when his father Yao Chang was a general under the Former Qin emperor Fu Jiān. (Who his mother was is open to interpretation; Yao Chang's wife, the later Empress She, was mentioned as his mother, but when Yao Xing later became emperor, he posthumously honored one of Yao Chang's concubines, Consort Sun, as empress dowager, which allows an inference that he could have been born of Consort Sun but raised by Empress She, but there is no conclusive evidence.) Not much is known about his life under Former Qin rule, other than that when he grew older, he served as an assistant to Fu Jiān's crown prince Fu Hong (苻宏).